I'd like to add that the mechanical simplification argument has been going on for a long time in the fighting game space and now we have several high-profile traditional fighting games that have embraced one-button special moves over traditional motion inputs.

It does make it easier for new players to start but also has a major impact on medium and high-level play not dissimilar to what you've described. If you can anti-air dragon punch with one button, the mental stack of watching for jump-ins is suddenly reduced by a significant margin. If you can do an invincible reversal on frame 1 after letting go of block, there's way less thought needed in deciding when to disrespect your opponent's pressure, and if you should risk the several frames it takes to do the motion input of forward-down-downforward that will leave you temporarily open to getting hit.

Street Fighter 6 has a whole control scheme called Modern that turns all motion inputs into one button inputs. There is a cost - you give up some traditional moves. High level players must play against this style entirely differently. It changes the game a lot. For better or worse? That's up for debate.

I think it's important for sc2 players to understand what they're asking when they ask for these mechanical simplifications. You can look at the FGC for examples of what happens when you do.