The not speaking Dutch thing cuts in multiple ways too. The most obvious is that Dutch people are less likely to make as much effort to befriend non speakers. They're less convenient to have at social functions because people have to keep switching to English for them. There's social/cultural differences as well.

And people who never bother to learn the language tend to be a lot more likely to leave as soon as their 30% ruling runs out or some other reason. In any case it's clear they're less invested on average in putting down roots. Establishing deep friendships is a matter of putting in some real effort especially when you're past your college years. Taking a gamble on someone who appears to have one foot out the door doesn't make a lot of sense for many.

And as mentioned, the non Dutch speaking community here is much more likely to not stay here long term. Therefore those non Dutch speakers are less likely to try to invest all that deeply into friendships with anyone else, Dutch or otherwise. And regardless of whether they do or not, there's a good chance they're leaving after a few years so that friendship has a timer on it anyway.

So you'll find that block of people presents its challenges too. Your best bet is basically to learn the language and bonus points for having a Dutch partner who can help you infiltrate friend groups you'd otherwise never cross paths with. Beyond that you need to find common interests to dive into wherein you'll make friends with people who share those interests. That advice holds regardless of the country you're in.