It’s the same as with Linux, GIMP, LibreOffice or OnlyOffice. Some people are so used to their routines that they expect everything to work the same and get easily pissed when not.
I don’t think that’s going to be the case.
The fediverse instances are just lacking a few things here and there to be Twitter/Reddit clones.
Most open source software sans few exceptions like Blender are like 15 years behind the curve in terms of features, workflows, and design.
Open source software is quite far from behind the curve.
There is almost no-one in my field in academia not using R and Latex. Combining it with Linux makes my life much easier.
Wikipedia is open source. Firefox. Chromium. WebKit. Android. Immagine your digital life without any of those.
Whenever I’m forced to use proprietary software I feel like I’m being held back. I know it’s mostly just a question of what you’re used to, but saying that open source is behind the curve is just not accurate.