Scanners stopped working for my business

I would un-install and drivers and re-install them. That just makes sense. Go to your mfg's website and see what you need to do so that you don't miss anything.

(it may be that your current drivers will work but only if re-installed. also - your drivers may be for el-capitan, perhaps if they have drivers for sierra or newer but not catalina, the newer driver would work)

Are your current drivers 32-bit Intel?

Hold the Option key and move the mouse to the Apple icon in the upper left corner of your screen.

Choose "System Information" and navigate to Software -> Applications

There should be a column on the far left of the list of Applications which will show if your current drivers are 64-bit or 32-bit.

Catalina will only support 64-bit Applications.

You have found a plan B that worked for you. Depending upon your particular scanner models, you may find that Hamrick Software's 64-bit VueScan may, or may not, drive the devices without the need for vendor driver installation. This may give you longer life from those devices where installed vendor drivers are unnecessary.

Disclaimer: I have owned VueScan Professional since 2012 without any additional software upgrade expenses. I receive no compensation from Hamrick for mentioning VueScan here. VueScan supports over 6000 scanner devices from 42 manufacturers.

Check with Brother and Fijitsu for updated drivers.

check that... I meant "far right" not "far left"

VueScan has a support page for each scanner that informs whether it can operate vendor driverless, or requires the vendor driver.