I've used dydns a fair amount over the years - both when it was free and a paying customer.
Now I run my own DNS servers for the domains I host on low-cost VPS. Adding a dynamic DNS service was the next logical step and that served quite well for over 3 years. If IRCC the two VPS cost less than the subscriptoin to DynDNS at the time I set them up.
A single VPS and a reverse proxy could be used instead to mitigate the need for a dynamic DNS service.