This is such a tricky situation that I've been on both sides of for sure! It's hard because you have a need for space and they have a need for social contact (both of which are genuine and very real human needs) so there's mutual exclusivity there, and nobody in this situation is really in the wrong - just in different situations.

At times where I've been burned out but know I have people in my life that need me, I'll send something that clearly shows I'm thinking about them but also is unlikely to prompt a long conversation that I couldn't handle (e.g. if I see a meme or video on a subject they will find relatable or interesting, I'll do that). It tended to work fairly well, especially since I had explained I can get burned out beforehand - transparency goes a long way in that!

What is surprising to me though is you have multiple friends who are all lonely and socially starved... I'm surprised they aren't all gravitating to each other! At times when I've felt like that, if I had someone in my friend group who wasn't burned out and wanted to talk to me I'd have stuck to them like glue and stopped talking to those who weren't returning my efforts or needed space as much. It's odd that that isn't happening here!