But seriously, I recommended Peanut plugs for a long time too. And some people have wonderful experiences with them. But I think that there is a lot more interactions going on behind the scenes that we are unaware of. Some devices just don't play well with others. For the most drastic example of this, look at Xaoimi devices with Iris plugs. They won't repeat to save their life. But Tradfri plugs repeat perfectly. So, depending on your setup, peanut plugs may be wonderful. But for me, they go on the YMMV list at this point.
Also, this goes to show you that you can have multiple different reasons your hub starts to slow down. There really isn't just one cause or one problem you can tie it to. And hence, there will be no magic bullet that fixes every hub every time. Just not the nature of the beast unfortunately. Sometimes I wonder why the hell I took up this hobby. Some days I wish I had a time machine to go back and slap myself before I bought that very first Wemo plug way back when. Hehe.