There is liability involved in this - of course there is - accident claims lawyers make fortunes out of people who get whiplash because they had to stop suddenly to avoid a passing badger and the government should be responsible for keeping woodland animals underground at night. That's the way the world has become. Diving didn't make it this way, but the dive industry has to exist by promoting an activity that could - and does - have fatal consequences, within a litigious world that rewards abrocation of personal responsibility by giving people money for having accidents.
Some dive shops adhere more strictly to recommendations from training agencies because - yup - this is covering their backsides. There is also the possibility that other local regulations may be in place. Take a driving analogy - you don't need a driver's license to buy a car, but if you want to drive it out of the shop, then I need to see some paperwork.
There is no reason that a non-certified diver, by any agency standard, should not be allowed to purchase scuba equipment. Maybe that's just the husband or wife of a diver buying them a new regulator for their partner's birthday, but it's also possible that local regulations do, indeed, prevent the sale of "life support equipment" to unqualified personnel. SCUBA is, by default, a life support system.
I do think that some rules and regulations are a bit daft, but sadly, covering of backsides is a requirement of existing in the modern world. Some will interpret the rules with more severity than others. Some lawyers are apt to do the same thing.
My grandfather was one of many British service personnel from WWII who learned to drive everything from jeeps to tanks on the battlefields of northern Europe, but after 30-odd years of driving without a license, he was forced - by government regulations - to sit a driving test, probably conducted by somebody who learned how to handle an SUV in the suburbs, and who is the better driver? They guy with a license who passed yesterday, or the guy who learned to dive back when diving was more science than holiday romance.
But - the rules say you have to have a card to dive here - so - there it is.
For the OP - after a 25 year hiatus, for sure I would recommend some form of review. If you just need a license, then enquire into the possibility of an "experienced diver" program. A lot has changed over the years, and you would not be the first experienced diver I have seen who chose to sit a current OW class.
Cheers
C.