Reliable talent, and expertise are great. But no matter how high you roll, you can only ever achieve what an ability check can achieve.
But I can do it sooooo many times. It's not like a wizard casting charm person can achieve more with it than that same ability check.
My argument is I can do a lot still and do it more often than spell slots can keep up. Spell slots can sometimes do more and bigger things on that limited scope. I don't mind giving up damage to KO people pretty much at will either, tbh.
Will I be able to cast polymorph? Nope, sure won't. But I'm still good IME.
Unless they would of spent 12+ hours traveling.
Then you can just cast teleport and catch up.
Around here we call that "wandering experience points". ;-)
At this point you're risking teleportation mishap and spending a lot of high level spell slots to avoid engaging in the travel and gameplay that I would get to play and experience when it comes to travel. Not really a winning argument IMO.
That's assuming I'm spending my available time your wizard, other wizard, and rogue wouldn't have because their spending that time also spending a lot of money on something that will be even more costly in the long run.
Then when (if) they do arrive they're down several high level spell slots for the fighting.
Or teleport to a cold climate, make a simulacrum, and teleport back.
That's 3 7th level spell slots and the possibility of hourly checks against exhaustion levels.
Most campaigns have some downtime. If not, then you basically banned the spell.
Simulacrum seems like a good use for downtime. It's not the only use for downtime and that downtime is also something martials can use. At the levels we're discussing a fighter, for example, can use the small standing army from his war room benefits to attack a despotic ruler in his castle and overthrow the local ruling class.
The war room feature in a bastion isn't something for which spellcasters (other than dance bards) qualify. How much damage does 10 veteran warriors and 1000 guards do?
Funny thing is the dance bard can have both the simulacrum and the standing army.