Yes you're probably correct. The R&D by the bigger names will be much greater, particularly on the anti-sweat, breathability technology of the material in football shirts, and I'm not going to disagree with you there. See Castore on that debacle with Aston Villa....
But I don't think there's much going on that's revolutionary about an embroided badge, and being able to employ an adequate stitching technique so the damn thing is straight and stays on the shirt. Also the cut and fitting of the shirts - a bit less square, so when you're wanting something to fit round your chest, neck and shoulders nicely, it isn't riding up your stomach because the sizing is all over the place. I don't think much R&D is need to achieve the fundamentals of basic seamstressing and sizing.
I'm not after the latest fabric technology, I just want a shirt that fits, and stays in one piece during the course of a season. Errea have been awful. Design-wise, 'ok', but workmanship and quality have been really poor. I have every Adidas shirt bar the 2021 home shirt, but only 2 Errea shirts - the first home shirt, which looks decent but fits terrible, and the maroon/gold 'keeper shirt which still has tags on. Massive difference is quality but expected to pay the same prices.
Adidas or Umbro next please.