I often claim that self hosting is a great learning experience. I encourage almost anyone who is serious about building software to start a blog. Both because it is good to have a portfolio of work that you have published, but also because it can teach you so much about how to run software. I’ve been running my blog exclusively myself for a little over four years now. I’ve rewritten my site more times than I can count in the last 7 years. Sure I don’t have the biggest audience so I don’t need to deal with massive load practically ever, but I a friend of mine did switch from Fly.io to self-hosting and he does have a big audience. His site gets to the front page of Hacker News quite regularly. Soon after he went self hosted he got on the front page of Hacker News with a load of 5% CPU and 77% memory. Not too bad for getting the hug of death from the internet.
Hacker News themselves is run on a single computer, with a second computer for fail-over. Since that post the are over 6M requests to Hacker News a day.
If you are worried that your server can’t handle the traffic, chances are you need to update your assumptions.
Aside: There are great DDoS/load protection services that you can use like Cloudflare and Fastly or you can run one yourself like the changelog folks do. These may eliminate some of the stress when your site gets a bunch of traffic.