The show hasn't aged well.
Watch on fast-forward when possible.
shareI think the problem is that from our viewpoint, nothing in the 1980s/90s has 'aged' well because technology progressed so quickly. You can watch an old b&w programme or something that's obviously from the 1960s/70s without thinking they're out of date, but the minute you watch something in colour, with almost familiar buildings, clothes and cars, it's always a bit of a shock to realise they don't have mobile phones, internet, or CCTV!
shareI wonder how much of this is cultural and tied to general British development.
As an American with a recurring fascination with Britain (including having actually been there and maintained relationships with Britons), I feel like the 1980s represents a much larger transitional period in Britain than it was in the United States. Britain in many ways seems to have modernized more slowly after WW II generally and to some extent have stalled completely during a lot of the 1970s. 1975 Britain seems closer to 1955 than 1985 does to 1975.
This makes early Morse episodes seem kind of anachronistic, as if the transitions in the 1980s had only partially started and most people were still clinging to social habits, lifestyles and stylings reminiscent of previous decades, worsening the sense of being "dated".
It's only worse having watched Endeavour, as Endeavour is an intentional period piece that makes its era a part of the show. Morse was not a period piece, it was meant to be set in the present, it's just that the present it shows is still partly stuck in its past because *Britain* in the early 1980s was just starting to emerge from what I think was a period of stagnation or at least very slow progression.
What I think is a useful comparison, even though the shows are much different, is the US detective show "The Rockford Files". Despite being solidly set in its 1970s era, it feels much less dated than Morse does. There are some obvious stylistic elements that contribute to being dated (Rockford's plaid blazers, everyone wearing a suit, etc), but overall the setting of LA in the 1970s appears to be much less anachronistic than the early 1980s Oxford portrayed in Morse.
The only question in my mind, really, is how much of this is deliberate choices by writers and production designers of Morse. Either because Morse was in his 50s or meeting the biases of its target audience who may have been older or more conservative.