How can I transfer pictures from camera to lightroom after Sequoia upgrade on Mac?

You could do what professional photographers do so they don't have to worry about computer operating systems recognizing cameras or vice versa. Those interfaces sometimes don't work when the camera is of an older generation and is no longer supported by the newer MacOS, or the camera is a new model and isn't yet supported by even the latest MacOS. The same things happens with Windows as well.

Professionals use a high speed card reader and copy or extract the image files right from the camera card. You can use a utility like Photo Mechanic to cull/organize photos directly from the camera or camera card, and then import from Photo Mechanic into Lightroom. Or you can use Apple's built in utility Image Transfer to read in image files from the camera card. Then import the photos into Lightroom.

One benefit of using tools like Image Capture or Photo Mechanic with a high speed card reader is that the transfer speeds are usually much higher than from the camera directly, and doing it this way doesn't run down the camera battery.

Image Capture of course is available on every Mac. My daughter uses Photo Mechanic and Image Capture, but I'm not plugging here for Photo Mechanic, there are other similar tools available. Those tools are not free but are relatively inexpensive, as are high speed card readers.

7 years old is not unusually old for high end cameras used by professionals or amateurs, that's not old at all, especially if you regularly have the camera tuned up and reconditioned by Canon, Nikon (or whatever the manufacturer is) as my daughter does with her various cameras. I think some of hers are 10 years old or more, she even prefers those over the much newer ones.

You can pursue card reader offerings on various sites such as Adorama, B&H Photo, Samy's or even Amazon and Best Buy. Be sure you get a suitable model for your camera card (e.g. SDHC, Compact Flash, CfExpress ...) and make sure the interface is best for your Mac (USB-C, USB 3.x, etc.), and while I think most are compatible with Macs, once in a while one shows up that seems to work only with PCs. Several can read more than one type of card. I have purchased some of these for my daughter's business, I generally go with a well known major brand (Hoodman, Sandisk, etc.) versus some brand I have never heard of before.