This is the same effect of wanting to watch an old film... If you want to do it the legit way, you will have to face all kind of hurdles, starting from finding a service provider that might have the film, then forget about all the modern audience "edits" they put on these things, at times the quality isn't even good, the audio tracks are messed up...

So you either give these jackals at least 30 to 60 minutes of your life (plus money) for the luxury of using their crap services and obtaining a half-assed version of what you want, or you just go to good old Forum McTorrent and get what you actually want for free.

The streaming service is a Cathedral: You've paid your tithe to the temple of HBO Max? Marvelous, please come in, my child and gaze upon our wonders! What? James Cameron's True Lies? It is not in our collection, please remain here and we can watch Commando together! It's just as good!

The digital copy is a Bazaar: You wander the booths of Prime Video, iTunes, and... Fandago!?! They assure you their copy of True Lies is the best! Ignore that other booth... you may save $2 but are you certain that video will still exist in a year?

And the whole time you know that just under the bazaar is the Underground/Black Market where all is preserved and all can be had, but you'll need to work for it.

From a moral PoV pirating old movies isn't a big issue, especially in cases where the original makers are already dead. At that point you're only feeding Hollywood bosses, shareholders and decendants. Same as torrenting music from dead artists. I don't care for Jimi Hendrix' greedy sister or 'Authentic Brands Group', which owns the rights to Elvis Presley's music. These people can create their own art instead of living off other people's work.

Physical DVD is the way. Praise Criterion

I don't know if I agree with you with this example. Sure it's annoying to find a streaming service but once done it generally works. Usually true with a film or TV show through the "forums" too, but not always. Sometimes it's the wrong episode, sometimes it's the wrong language, sometimes one particular show keeps buffering even for no obvious reason. And even though it's quite rare, you never know until you're sat with your wife or friends watching it, because who checks the show in advance?