I can really relate to the idea you are trying to promote. Working under constraints, as you said, forces you to think out of the box and take what ever technology you are using to the limit.
I do think however that associating this issue with vanilla js as an alternative to this or that fw or as you call it “old school” methods is not serving the point.
A simpler example of working under constraint might be limited resources — 1gb of memory will force you to write efficient code, supporting additional platforms using existing code might force you to think out side the box and use more appropriate tools etc…
Any way, nice write up — recommanded ;)