With how invasive and creepy big tech has become, just using mobile apps with internet makes me feel 気持ち悪い as the Japanese would say. Desktop, that too with Linux, all the way for me.
Depends what I need, if it's downloads related (or if I'm already in my computer because of my work) I'll use the desktop but anything that is not that mobile for sure, although the mobile just updated and I'm quite lost
Desktop without a doubt. I installed some games to my phone and I tried to play them but it lags and stutters, not good, desktop no problem. The only thing worth using the mobile for is social use and reading. Also forget using mobile for watching movies since it's more enjoyable on a large screen.