As you say, this is hardly a representative sample. There is a survivorship bias here. There are probably many SaaS products which aren't well known puttering around this MRR mark. Most probably the ones who scale beyond this point are more interesting to investors and few decide to turn down offers. VWO is one of them.
I think it would be interesting to get a count of companies post-$5M who are still unfunded. It’s easier to stay this way because usually these companies have grown on the back of content marketing and WoM referrals. As a result they are cash rich and can afford to hire great talent to scale the product further.
The race from $10M is actually much more interesting because vertical products now start spreading horizontally and creep into the territories of existing market leaders. This usually heralds an increase in marketing expenditure as these companies now like to sell larger deals to bigger companies.
You make a great point about how VCs contribute with knowledge. Instead of stumbling around and learning from errors, having good VC mentors could help scale faster. It’s always great to get inside knowledge of other people’s problems and learning from their mistake ;)