It is rarely an issue in practice. There are workarounds to minimize connection resets. Using ECMP hashing on routers and a tiered load balancing topology are important.
https://vincent.bernat.ch/en/blog/2018-multi-tier-loadbalanc...
https://blog.cloudflare.com/high-availability-load-balancers...
https://engineering.linkedin.com/network-performance/tcp-ove...