This is all true but the really big change IMO was the transition from a travellers free festival to an organised profitable business. I can’t remember the full details but the clashes between the private security firm and travellers that caused the event to be cancelled for a year. When it returned there were police on site with better organisation and more infrastructure. Progressively more technology, fencing and perimeters were needed to stem the tide of ticketless punters. Glastonbury rapidly got organised in the early 90’s attracting bigger names (not just bands but vendors and investors).