Cynics would call the apps on f-droid feature poor. But for me, the FOSS apps that I use day to day tend to just do the thing you need them for, no more. There's no telemetry overhead, they tend to use fewer dependencies, are less likely to be built on heavy frameworks like electron. Of course there's heavy sampling bias involved in this since I specifically select apps that feel snappy and light. But this has always been true for linux desktop apps, too. My favourite comparison is the size of pdf viewers. I have never lacked a feature from the Adobe pdf reader. The 400KB binary of evince totally sufficed, and it used much fewer resources at runtime, too.
I really hope that this ecosystem can push the boundaries of what's possible with lower-spec hardware, even if just to hold the mirror to the big platforms.