I've been searching for a decent dumbphone for the better part of a decade. Unfortunately, I cannot really say I've succeeded. In that time I've tried the following phones: Nokia 225, Punkt. MP02, Mudita Pure, Doro 7030 and now a Nokia 2660.

My list of requirements isn't long: 1) should make/receive phone calls, 2) should make/receive text messages, 3) have physical buttons and 4) preferably use 4G and be able to create hotspots (the last requirement, I have deviated on occasionally, like with my current phone). A requirement 0, if you will, is that it needs to do these things at high quality. But in one way or another, they suffer wildly in either hardware or software, or both. Often to the point, where I wonder if the creators themselves use them.

The two Nokias unfortunately have quite a few ad programs (like Facebook of all things), that just clutter up its menu (but which I can thankfully just ignore), its T9 dictionary is weak (though this will be a recurring theme, they are all bad at doing T9 dictionary typing), and its text message storage is severely limited. The Punkt. MP02 had high quality hardware, but again its T9 typing was frustrating, and eventually mine just bricked. The Mudita Pure was probably the worst one, though: it only supported characters A-Z, despite being developed in Poland, which is frustrating when living in a country, that regularly uses characters beyond that. The Doro 7030 had bad buttons, that often wouldn't properly click, leading to missed characters while typing, and it had an annoying behaviour, where sometimes it would just miss calls, and its T9 typing was abysmal.

I still have all the phones (except the Mudita Pure, which I sold to someone in Greece, even though I explicitly warned them it would not work at all with Greek letters, which they later confirmed, as it was just showing squares), and I am generally sad, that it feels like a bit of an electronic waste.

And why not a dumbed down smartphone, then? My requirement 3 isn't debatable, I loath touch screens; they are - for me at least - the bane of modern existence. I cannot avoid them entirely, but I can lower my own exposure. For example, when I bought an induction stove top, I made sure to get one with knobs.

Maybe when I feel ready again, I will try my hand at another[0]...

[0] https://dumbwireless.com/collections/phones

My dumb phone solution: an Apple Watch with a cellular connection.

You can’t browse the web or install addictive apps. But you can get your mail, texts, and phone calls and you can listen to music, check the weather, and navigate with a map. It also has a physical dial you use for scrolling.

There’s enough friction with the device that you aren’t glued to it, but it’s functional enough that you won’t miss leaving your phone or wallet at home. It mostly becomes a watch first and foremost but also has the perfect feature set as a phone replacement.

Perhaps its not quite 'dumb' enough for you, and they have yet to ship so no one can really speak to the quality but this product https://clicksphone.com/communicator might fit your needs. I'm thinking to get one myself but not yet decided. Will probably wait for a review or two.

I have a Nokia 6300 4G that matches all of your list of requirements, including acting as a hotspot.