If you don’t want to go full Cloudflare you can mitigate DDOS using these kind of technique locally.
https://blog.nginx.org/blog/mitigating-ddos-attacks-with-nginx-and-nginx-plus
Cloudflare will be a lot more effective in case of attack. But I don’t think most people need more than a few mitigation rules. If DDOS really come, there are very few things you could do to mitigate anyway.
Don’t think so, they aged so well!