I haven't watched your Best things video yet, but something I've been thinking about here: time was there was no knitting or crochet or cross stitch community. There was just needlework, and it included everything from mending stockings to spending the summer making socks for next winter to embroidering handkerchiefs.
And sure, people might have personal preferences and better or worse skills, but there was no shock that the knitter started a crewel project after she finished the cardigan.
Your points about "focus" (ugh) are familiar. It's almost like the medieval guild days which were dominated by professionals, s opposed to now, when we're supposed to be doing this mostly for fun.
I grew up being taught, and doing, needlework. Cross stitch, needlepoint, crewel embroidery, rug hooking, knitting, sewing, crochet, beading. I found a lot of overlap and a lot of usefulness in being able to combine different skills in one project.
Like yourself, I just don't see the point in limiting myself. Yes one has to keep a handle on buying materials, but a lot of the materials overlap too.
Okay, of to see the Best video. Great topic!