Mainly agree, but maybe can be a bit more generous.
"30" sounds low to me, having worked in large companies for many years. Sure, the number of people you worked super-closely with for years is maybe in double digits but you probably know a lot of other people by reputation (which is still good signal) and there may be low effort things you can do for them. I try to, anyway.
This is a hidden danger that I only understood late in my career. I like working at small companies. You can contribute big things relatively easily when there are only a few contributors to begin with. You can build something and nurture it over time - anything from a technical asset to a working relationship with a colleague. You get a more diverse range of things to do because not everyone has to be pigeonholed and not everything needs approval from three different committees. You don't need to constantly try to do "high visibility" projects that will show up in your promotion panel because everyone in the company knows if you're good and the right person to take the lead on the next big thing anyway. You don't need to job hop every year or two to find interesting and well-compensated work for the same reasons.
But then after a while you've only worked in a few different places and with a few different people at each one. Your professional network is much smaller than someone who worked for a variety of big name tech giants in that time doing no-one-really-cares-what and climbing the career ladder by job hopping.
I'm really not bitter. If I could go back and tell my newly graduated self how their career would have gone a few decades later they'd probably still have made very similar decisions even with that knowledge. I've enjoyed many of my roles at small companies immensely and I can't think of many less attractive jobs in this industry than being a cog in the machine at some tech giant whose primary contribution to humanity is turning us all into spyware targets and then ad targets.
But it's undeniably true that sometimes in a tough market - even many years into a career and having reached the equivalent of staff/principal level or followed the independent/entrepreneur route - you can still end up knocking on the front door of an interesting employer or doing the recruiter thing to make a move when habitual networkers with similar YOE would not need to stoop so low because they'd find something via someone some other way.
"30" sounds low to me, having worked in large companies for many years. Sure, the number of people you worked super-closely with for years is maybe in double digits but you probably know a lot of other people by reputation (which is still good signal) and there may be low effort things you can do for them. I try to, anyway.