SSH into private machines from anywhere using Cloudflare Tunnel

Wireguard, with dynamically-updated DNS resolution to a residential IP is very solid for a free tier and has the key benefit of zero third-party (i.e. not controlled by you) dependencies, other than the IP provider and the DNS resolver, which is a commodities business with low switching costs. Cloudflare is very nice and will be around for a long time, but it's still a third party dependency.

As it boils down, the OP's solution is "free" as in money but not as in freedom for a certain set of requirements.

Basically, going with CF trades-off some freedom for the considerable/legitimate protection benefits of being under the "cloudflare umbrella". It's probably a good trade for this moment in time. But rational people can disagree about whether it's a good trade when you broaden the time horizon to 5, 10, etc. years.

Like all things, it depends on the requirements you're building for.