There's a few answers to this because it can depend on a lot of things.

Basically there's a lot of ways to scan film. Some are very slow, some are very fast. Automated systems can be incredibly expensive. The best dedicated film scanners are no longer made and can be very expensive to obtain and maintain. The dedicated systems with automated scanning can be extremely expensive. Automated mechanisms also specialize on strip film or mounted slides.

Currently made systems mostly rely on camera scanning, which is pretty good these days. There's one that does slide carousels and I think they made a system for strip film. There's also an automated strip film system by Negative Supply.

If you don't have an automated system you have to manually mount each strip of film, scan all 3-5 frames, take it off, put it away, grab another, keep going. Or do that for each individual slide. Flatbed scanners are among the most common ways to scan film (though it's not nearly as good as camera scanning), and you can do a bunch of frames at once. But they're usually very slow and takes a few minutes per slide.

There's just a lot of ways to do it but it almost always involves a lot of manual intervention even with the fastest systems.

Besides the actual scanning you have to deal with the media you're digitizing too. Re-sleeve, remount, and re-sort anything that might be deteriorating and in poor condition. Clean major dust off the frames, decide if something isn't even worth scanning, wear gloves and handle the film carefully so you don't damage it, keep everything in the organization system so it isn't lost, organize it physically and digitally, tag the photos according to date and content (data doesn't exist if it isn't organized and/or searchable), decide how much editing you'll do to each frame, and adapt your procedures because of special circumstances.

You can scan everything and just toss it up there. People do that all the time, but it's still a very physical and manual process. And if you're after quality and organization, it can take even longer.

You get to see so many cool memories from the past vividly restored in very high resolution. Properly exposed, developed, high quality, and safely stored film can deliver some amazing digital results. Far better than a lot of people realize (though film doesn't have infinite bazillion K resolution like some redditors may say haha). It's very rewarding! But it's also very slow and very repetitive.

Bit of a random explanation but hope that makes sense!