As a straight male I’ve always found dating men for friendship was a lot harder than dating women
The upside of all that is that most men don't usually take it personally. Like, I can throw out a text to someone I haven't seen since college in another state and we chat like old times (you know, minus the 5 years of catching up). So it's not like they ignore people on purpose. I guess life is just busy.
I have no clue how to meet truly NEW freinds though. Meetups are so flaky and a lot of my tech/gaming circle is probably inside anyway. At best I met some closely connected friends that were ex-coworkers I never talked to.
All my male friends are either from college or work, and like you said they tend to forget you if you don’t follow up.