i really fail to see how equalising choices is at all a bad thing?
I fail to see how it is automatically a good thing and if people are choosing underpowered options that implys the game is fun for them with those imbalances. I know it is fun for me.
'Oh no, i get to pick the class/subclass/species/feat/item i want to use AND get to mechanically contribute on the same level that everyone else is, this game is ruined for me',
Except that class mechanics are not a major driver in that. I am playing in one game right now as a Monk and I am contributing as much as I want.
I am played in another game today and the Barbarian in the party way overshadows other players and not in a good way. In that game I am playing a high-charisma Rogue but I almost never make a Charisma check because he is always making them and Charisma is his dump stat (I think he has below a 10). Would he be overshadowing me less if I was a Wizard? Unlikely!
That is an example of two "weak martials" that are contribnuting (one of them contributing too much).
it only reduces the meaninfulness of choices if you think that having multiple equally valued choices to pick from makes them less meaningful.
Two things. First, I think putting fluff into choices to make them more mechanically balanced would make them less aesthetically pleasing and less meaningful.
Second the relative power of a specific choice is one thing you are considering when you are making a choice and if you balance them you take out that variability and that choice. For example, aesthetics aside; if I want to choose an OP option I can't do that if all the options are the same. Similarly if I want to take an underpowered option I can't.
People want to play "god Wizards" and other people want to play "dumb fighters" and others still want to play support characters along for the ride and if you make all options equal those purposeful choices go away.
equalising viability and effectiveness lets people focus on the actually important part
Except the effectiveness is often an important part of the decision.
when choosing options which is making their character how they want to make them, or to use a food metaphor, by your preference it would mean the size of our serving is determined by the meal we pick but they all cost the same price to order, the martials only have a small portion just because they wanted the soup, whereas casters have an entire buffet table, while what we're saying is why doesn't everyone recieve the same sized plate so everyone they can eat what they want to eat and still get a satisfying portion of their meal.
This analogy is not accurate to start with unless you specify a specific level range. But to address this more head on, there are certain foods that are undeniably better for you and that is not correlated to choice or price. Further expensive options (like meat) are often objectively worse for you than other less expensive alternatives. Yet you are allowed to choose what you want to eat in the restaurant - good choices, bad choices, expensive choices, cheap choices. When you pick something off the menu you get the sides that go with it, it comes in the size it comes in and the menu offers all of the options, including the buffet. If you order the steak though you don't get to eat off the buffet.
Similarly, you open the PHB to a menu of options, certain sides go with certain options (action surge with fighters, buffet with casters) ... you order the size plate you want and the sides you want.
No one should be forced to play a Fighter or a Monk or a Wizard, but you should be allowed to choose that "small plate" if that is what you want to choose and no one should have to order off the Wizard the buffet.
Further I will go back to an earlier post, I pointed out that giving martials spells would balance them better than they currently are, that is giving them the actual "buffet" option the Wizard gets and would be far easier than other ideas to balance.
Would this fix it for you - spells (i.e. the real buffet) for all? I am guessing the answer is no, so you want everyone to get the buffet, but you don't really want them eating off the same buffet/
yeah, but even if there are trap options for casters given that they're 99% spells it's generally significantly easier to swap one out if you discover it's awful, at worst some casters are stuck with it til their next level up and there's a vastly larger options of alternate choices to pick from when they do get to change it, some martial trap options are near entire subclasses it feels like or ones you can't back out of unless your dm lets you retcon your choice.
I don't think there are actual trap options in the subclasses, a couple are very underpowered, but even there they are still generally viable. Moreover though Tasha's gives you the option to change your subclass if you do find it to be a trap. If your DM does not follow those rules that is what it is, but I think that is a table problem, not a rules problem.
Here is a hot take on trap options - IMO investing in a high Constitution is a trap, probably the most common trap option I see in play and one many players deny is a trap or worse suggest is optimal. Many, many players make Constitution their #2 stat regardless of class but unless they are a race/class/subclass that works off Con (Dhampir/Barbarian/Rune Knight) most characters would be better mechanically with Constitution being their 4th or 5th highest stat. The ramifications for going with say a 16 Con and 12 Wisdom on a Fighter or Rogue or even Wizard, instead of reversing those, is generally going to gimp your character more than your subclass selection will.