I had one back in 2001/2002. I'd have to look at my records. I got one with extra storage space and also got the lifetime service at the time so I didn't have any extra fee. It was great. I loved it a lot, the way the recordings worked and all that. But unfortunately, it was an older model and our apartments at the time got another service provider and it was not compatible anymore. It couldn't do HD. We didn't have a HD TV at the time. Once we did, I couldn't use it. Never could use it again and never really wanted to spend the money for another. I had Uverse for years after and they always told me I could not use a Tivo with the service and had to use their stoopid cable box.
I actually still had it all these years sitting on top of my old VCR player in the TV stand.

. I just threw it out when I moved in December. It was sad, but it wasn't useful anymore.
Now that I cut the cord, I have some of those functions back I liked about the Tivo. Not all of them of course, but YoutubeTV has a great cloud DVR and so does PhiloTV. All way better than the mess those cable boxes do.
I wouldn't really know how I would incorporate a Tivo now that I cut the cord and use the different things. YoutubeTV, Philo, Amazon Video, TennisTV, Netflix and sometimes Hulu, Curiosity stream.
So when you say they will get Roku, one could then watch everything that one can watch via Roku right now? But how does it work with the programming stuff then since that is all streaming. Tivo's magic happened with the regular channels so not sure how it would pick up stuff from say youtubeTV or any of the other live streaming services and still do its thing.
I don't have OTA, I get all my locals via the YoutubeTV app. I'll have to so some research.