I'd argue it's even worse, and network programming wise I'd argue that every custom implementation of TCP/UDP was broken in the past and lead to a lot of remote exploits, and eventually was abandoned due to maintenance costs.

Just think about the shitshow of the source engine, for example. RCE'ing in the wild for what, 14+ years now? Took a long while and a lot of steam runtime sandboxing code to fix the decision to use a custom unsafe networking code.

It's been decades now that people routinely do kernel bypass on servers using e. g. Solarflare NICs with OnLoad. You just write your networking code normally using BSD sockets API, and LD_PRELOAD the OnLoad SDK which will intercept the socket API and perform a bypass. You get 90% of the latency benefits of kernel bypass without modifying your code, which still runs everywhere.