Yes, but as was explained earlier in the movie, that's not how time travel works in the MCU. Changing the past does not change the present. As Scott said, Back to the Future is just a bunch of BS.

I find it a bit weird that considering the many, many unrealistic things that have happened in the MCU to date, this is where you have a hard time suspending your disbelief.

Well that's mainly because those time travels rules are kinda BS. And even the MCU realizes it, considering it mentions that literally everything else with time travel doesn't work like it.

It also shows at the end that Cap goes back in time to replace the stones... Except that under the MCU's rules, when he goes back to the past he would just go to a different alternate timeline which already had stones, and not the stone-less timeline he went to before. (Meaning that somewhere out there there's a universe with doubled stones and one going to shit cause it has no stones.)

Cap also wouldn't appear in the end as an old man because more glaringly, the past does not change the future. So there would be no old Cap because Cap only went back in time to an alternate timeline, and not the main one.

Hold up. The confusion in my brain right now..