Scanner compatible with Catalina

Most scanners should be compatible with Catalina, what may not be compatible is the included scanning software if its 32 bit.

However, you don't need the included scanning software unless you want all the specific features it offers.

You should be able to use Apple's built in Image Capture app with your current scanner, as well as with any new scanner you buy

See here: Scan images in Image Capture on Mac - Apple Support

The Canoscan 9000F will work with the right software, i.e. VueScan,  Download and try the demo version before you buy. It runs my very old Canoscan 8600F scanner quite nicely.

I found VueScan to be better than the software that came with my 8600F and my new Canon multi purpose unit (MG7720).

The CanoScan 9000F is on the list of scanners supported by the VueScan scanning software. If the scanner worked OK for you before, it might be cheaper to buy a copy of VueScan than to buy a new scanner. You can try VueScan for free. It will put a watermark on scanned images until you pay for it.

I've used VueScan for about fifteen years, currently with the scanner in a Canon all-in-one printer and with a Nikon film scanner.

I suspect that Image Capture requires a driver from the scanner's manufacturer. It would be a lot of work for Apple to (in effect) write their own drivers for all the different scanners out there. They probably rely on the presence of a scanner driver that provides a standardized interface.

Canon's support page for the 9000F indicates drivers only up to MacOS 10.13 (High Sierra).

The 9000F Mark II does have a Catalina-compatible driver.

VueScan supports the 9000F directly because its author reverse-engineered Canon's driver (as he did for my ancient Nikon LS-40 scanner).

Scanners like printers have used a standard driver for many many years. Both on Mac and Windows. Its part of the Universal aspect of the USB spec. Macs have been able to directly detect and use scanners without a specific driver from the manufacturer for a long, long time.

There is no requirement to install a specific driver or even the Scanners software for a scanner at this point in time.

Drivers and extra software only serve to enable specific features of the scanner that may not be covered in the generic built in scanner interface driver on Mac or Windows.

Its always best to attempt to use the scanner directly without any added software and only install drivers and software if extra features are required.

I give a +1 to Phil's suggestion. After suffering with wonky scanner software furnished by the scanner maker, I now use only Image Capture and have never had to add drivers.

Thanks Allan.