I just took a look at Fly.io, but one thing I liked about Heroku was the fixed pricing; for a small site I could know for sure exactly how much I'd be paying (or not paying) each month. Fly.io looks good for an actively-monitored business product that wants to scale and is trying to be really efficient with spending, but doesn't look so good for a fire-and-forget website that gets updated once a month or less.
For websites, you're looking at Vercel, Netlify, or Cloudflare Pages. I use the latter and the breath of Cloudflare's platform is impressive and keeps growing every day!
