Depends on the table and how much the min maxing occurs and how high the game goes. If you only play lower level games it's a bigger deal than you realize. I know tables that don't play past 6 level or so and +1 is huge. But the main point is "Trap and flavor" junk that add nothing beneficial to the mechanics are "JUNK", this is the kind of stuff that bloated and eventually sunsetted 3rd and PF1e. Most people I talk to on the Internet forget most DM's have little to no experience and don't adapt for bad dev decisions.
No, even at lower levels it's not a big deal. It's called having a variety of encounters and role playing a story. If one person dominates all combat encounters, then it is quite obvious that the encounters are not balanced nor varietal. Everyone always insists the +1 makes a HUGE difference - it doesn't.
When a player min/maxes damage, they exclude other things. And that is part of the fun developing characters, trading off this for that, and seeing how much you can squeeze out of x, while limiting y's growth. There is nothing wrong with that. But to insist that it suddenly makes other characters feel worthless in a game with three pillars is ridiculous.
And this doesn't even account for level change abilities, ASI's growth, and feats choices. I mean, I once had a 12th level half-orc with 192 hit points, a great armor class, able to rage and reduce damage, and could pop back up after the grind of getting me down from zero. That is definitely a way to min/max (8th level fighter, 4th level barbarian, 4th level cleric). It all followed the story, and the choices were rather natural. But it made him ridiculous to drop. No one complained that I broke the system. Yet, give someone an extra 5 points of damage each round and certain people lose their minds.
The variables on how much things like a +1 effect the game are numerous. And in the end, it really is just players wanting a +1. It is the same debate that was carried out over races/species. The long whiny complaint of, "I would play a half-orc wizard, but his intelligence sucks!" Or, "My elf fighter is worthless next to the dwarf fighter in the party." It was a mere +1 difference, yet the complaints were endless. And worse yet, it ignored the benefits the half-orc or elf brought. That ability to pop up after being taken to zero, or that ability to long rest in 4 hours - ignored. Nope, it was only about the +1. That is why Tasha's was sooooooo beloved. Not because of its cool spells or even its sub-classes, but because it finally let players min/max just a little bit more - +1 more to be exact.