nginx is never fine for load balancing, they put basic features like metrics behind the paid edition. It's not sane to operate in production.

https://thehftguy.com/2016/10/03/haproxy-vs-nginx-why-you-sh...

I work for a billions company. Nginx is still fine. Youll need to be prepared to pay for better operations, management, visibility, and protocol support. You can either pay them or build it in house, but you will want to pay.