Just want to clarify - after looking at Porkbun's DNS offerings, it does not appear they do DDNS either. Is that correct? So they are not any better than SquareSpace for that service. Porkbun does have an API interface.
It looks like Namecheap has DDNS support (at least I get valid-looking results when I search for that on their website).
I haven't changed registrars in 10+ years. I am in the same boat re. Google -> SquareSpace. Is DDNS deprecated in favor of API's across the board? It looks more complicated to set up.