Films, papers, and development chemistry are/were always things that were in constant flux, with formulations that changed every couple of years and products that came in and out of existence. Rather than getting upset about the changes or the discontinuations, I always found it best to just keep moving on, developing my skills to take on a new version or a new type of film or paper, finding its advantages, and learning how to use them for the imagery I wanted to produce.
I shot a lot of Plus-X back in the day (1960s/early 1970s), to the annoyance of most of my friends. Most of them expected Tri-X looking images and didn't like the Plus-X look. I liked Plus-X in Acufine more: longer toe, less highlight blocking.
But Plus-X changed, and so did Tri-X, and I often shifted to other films in the 1980s. Agfapan 25 and TMax 100 (after I learned how to process the latter) became my standards for a spell that lasted through the '90s, alongside Ilford XP1, then XP2, then XP2 Super, and Kodak CN400 chromogenic. All of it good, all of it different from one another.
Nowadays I buy film in batches, usually five to twenty rolls (or packs) at a time. I buy it to learn it, to get something out of it, and hopefully to produce a project. When it's used up, I consider what next I want to do ... often the same, but often different.
There's no going back, there no "finding the equivalent" ... There's only pursuing my photographic visions.
I just ordered ten rolls of Washi W-type 120 format film. Orthochromatic, ISO 12-25 depending on the light, a hand-laid emulsion on Japanese Kowo paper. In my 6x6 equipment, I'll have 120 exposures to work out what it sees and how that bends and creates my photographic vision with my different cameras. I'm looking forward to it.
I guess this is my daily entry in the "philosophy of photography" sweepstakes.
... 🙂
G