I think that it depends on what you are doing. If it's just VPSs, then you may be able to scale farther than you think with DO.
If you want to do Lambda or use two or more of the other 1,000 AWS services, DO probably can't do it at all. But also consider things like Cloudflare or Netlify if they are applicable.
You will pay a high premium to use AWS. That might not make sense if you aren't a funded startup or don't need the broad range of services.
DigitalOcean Spaces offers S3 API compatible object storage (i.e. you can use any S3 client library without modification) and a seamlessly integrated CDN that is markedly cheaper than CloudFront: https://www.digitalocean.com/products/spaces/
If you want to do Lambda or use two or more of the other 1,000 AWS services, DO probably can't do it at all. But also consider things like Cloudflare or Netlify if they are applicable.
You will pay a high premium to use AWS. That might not make sense if you aren't a funded startup or don't need the broad range of services.