It's easy to fall into the trap of doing things the simple way or the unity way. To avoid it you have to go out of your way a bit and apply the same rigour as if you were writing your own engine.

Not making heap allocations in loops/Update and favoring object reuse really isn't comparable to writing your own engine.

I didn't say it was. I'm just saying that you can't allocate and instantiate all over the shop just because it's a GC language.

I've never encountered a stuttering issue in any Unity game I've played.