If it's licencing issues, why cant we at least have more Sony first parties?
I'd say it's licensing issues. Depending how they were signed, the license for PSOne Classics (or PS2 etc) could be for a PSP or PS3 version only or time limited to a certian amount of years.
In case of 1st party games, in many cases there can be licensing issues with music tracks, real car brands, real weapon brands, sports clothing brands, sports teams, sports players, 2nd party team who developed the game and in the case of older games (around more or less PS1-PS2 age and earlier, it was common that in some big games there were some important people in the game, as the creative director in some cases that got a portion of the royalties from the IP or the game and in some cases required related paperwork to get their ok for future ports and pay them part of the revenue from these ports.
Sometimes these companies or persons are no longer available, in other times they consider that the combined costs of to renew these licenses combined to the one of making the paperwork needed for a new release (fill the metadata of the store, do legal work, art assets needed for the stores, some testing to verify it works in the new platform, age rating process and fees etc.) is bigger than the money that the publisher (or Sony in case of 1st parties) estimates that this new version will generate.
Or in other cases, they may have the people who should work on it busy with other things they think have more priority or are more important becuase may generate them more money.
Or maybe people who should work on it may be busy with something else: in case of PSN stuff maybe things like the recent improvements we saw in PS cloud gaming improvements (PS5 games and features support, incresing streaming quality to 4K + HDR + 3D audio), preparing the OS part of PS Portal in PS5 and PS Portal side, making the Sony Pictures Core app and its partial integration in PS+ etc., a few months earlier the PSVR2 integration, or adding support for the recently released or announced gamepads or headsets etc. kept some people busy.
We also saw some Sony job offers to make new emulators and improve existing ones. This may mean that they prefer to wait to release some titles that may cause incompatibilities in the current emulators or until the emulators are good enough. Or that they may be working on releasing somewhere in the future PS1/PS2/etc classics on PC or mobile, probably on their own PC/mobile PSN store.
Another possibility is that they are waiting until the planned release of PS Cloud gaming on smartphones, tablets and smart tvs (plus maybe PS Portal too) somewhere in the future.
These things would expand their potential sales for each classic game released, so maybe are waiting for it before releasing them until that moment because -at least for some games- right now the potential sales wouldn't be enough.
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