OK, who can recommend a domain name registrar that:

- Is boring and dependable and has a rock solid track record
- Has a really good UI, including on mobile
- Supports as many TLDs as possible
- Isn't likely to get acquired by someone else
- Ideally supports multiple payment methods as insurance against accidental card expiry

I'd settled on Google Domains... but they just sold themselves to Squarespace! https://9to5google.com/2023/06/15/google-domains-squarespace/

Google Domains shutting down, assets sold and being migrated to Squarespace

Google Domains is "winding down following a transition period," with Squarespace taking over the business and assets...

9to5Google
@simon I use https://porkbun.com/ and recommend it. I think it hits all your points.
porkbun.com | An oddly satisfying experience.

Porkbun is an amazingly awesome ICANN accredited domain name registrar based out of the Pacific Northwest. We're different, we're easy, and we're affordable. Use us, you won't be sorry. If you don't use us we'll be sad, but we'll still love you.

porkbun.com
@ve3mal I can vouch for Porkbun as well, but in my experience their selection of gTLDs isn’t the largest. I can only host 2 of 5 domains there due to them not supporting the other TLDs (sadly). But if yours are supported they’re seemingly perfect.