I have an M1 Air at home and my work desk has an M1 Mini. Both are doing really really well. The Air still sips battery and handles all kinds of multitasking really nicely.
I often run up to three user accounts on the Air (an edge case, I know): one main personal account, one account signed in to my work's Apple ID, and a third I use only for writing, and which has no email, Messages or any notifications at all. Even with all that, it stays very responsive. I catch myself ogling the M3 Airs and, frankly, I don't need one. Everything on the M1 Air happens easily fast enough.
Also, on my remote work desk at home I just a few weeks ago upgraded my M1 iMac to an M4 iMac. The M4 is definitely snappier. Things happen immediately where there was maybe a tiny pause with the M1. I know it's probably 2x as fast in benchmarks, but for me the real-world difference is fairly subtle. I mean, I'm sure my next Handbrake encode will be awesomely fast but if I'm being real I probably could've done with the M1 iMac for quite a while longer, judging by how well my work M1 Mini is still cranking away wonderfully.