I should be clear that I'm not criticizing Nikon. They make excellent cameras and excellent lenses.

Canon EF lenses go back to 1987 and are compatible with modern DSLRs. Not as far back as Nikon, but probably far enough for most working equipment you'd buy or rent.

My apologies, I didn't read your comment as an implicit criticism, and surely didn't intend to come across as if I did.

(I guess it could be argued that everybody makes excellent cameras and lenses nowadays - the cheapo end of the market being all but taken by camera phones, whatever is left of 'real' camera makers all have excellent quality sensors and glass, leaving your choice more to features and ergonomics than image quality as such.)

It's probably also worth noting that with advances in manufacturing, new - relatively cheap - lenses can be quite good, even compared with older "high end" lenses.

New Sony lenses are for example quite good.

The situation is different if Obe has (access) to an existing collection of great lenses, obviously.

It was important to me, which is why I have a D5300 - I like shooting the same late-60s, early-70s glass on which I first learned. But the DSLR market is relatively niche, and odd therefore; most casual users not satisfied with phone cameras (and most are!) go for a point-and-shoot due to their relative simplicity.

I bought a DSLR and almost never use it anymore. (Obviously not a photographer.) Should've bought a mirrorless with a pancake lens and WiFi/BT so I wouldn't have to juggle cards or cords.

Mirrorless is another good option, but unless you plan to take advantage of the interchangeable lens capability, P&S is cheaper and easier. The Nikon Coolpix A900 in particular I can recommend based on your use case; I had one before the D5300 and, had I not needed a full-on DSLR to support long-range wildlife photography and the like, it would have done me just fine.

(It's important to consider how something fits into your daily life, too. No camera is useful if you don't have it when you want it, and I wouldn't have chosen any DSLR did I not already carry a satchel with enough room to tote it along every day.)

I have found that a Sony RX100 is a rather nice compromise between picture quality and portability.

I have been close to upgrade my old DSLR since I want a better sensor and some really good glass for indoor photos, but I'd use it twice a year. I might buy one when I retire.

I think in practice most of the market don't care about using 30+ year old lenses. And if your using manual only lenses, you have many options on which body you want to use.