At its peak, TiVo was a household name...and in hindsight, it probably would have been possible to keep it going with relatively small amounts of effort.
For starters, they weren't all that great to their base - the folks with the lifetime subscriptions. They were the early-adopters and the enthusiasts, but they ran into issues once the lifetime subscriptions were tied to the analog boxes and the cable companies stopped offering that service...in such cases, the customers had to choose, and at the very least, some of them were unlikely to choose to continue with TiVo. It probably didn't help that some of those boxes required dial-up connections to get guide data, and they weren't exactly upgradeable to wi-fi.
From there, cable companies competed with first-party DVR boxes...which everyone hated because their UI sucked and was slow, but it came bundled with cable service and the cable companies actively supported and marketed them, so lots of people used them instead. Had TiVo offered an onboarding service, where TiVo would get a CableCARD on the users' behalf and send it to them preconfigured, that may have helped justify the purchase.
TiVo was already at least some living rooms; they could have gone toe-to-toe with Roku and Amazon Fire Sticks...and I believe the later models *did* allow Netflix streaming and such, but it was too little, too late, and TiVo didn't have retail space in the same way Roku did. For sure, Roku would have won on price, but it likely would have been possible for them to have leveraged their brand recognition.
Finally, the nail in the coffin for TiVo was that they didn't lobby to retain the legal mandate for CableCARDs. I had a SiliconDust HD Homerun Prime, and I loved it for the time I could use it, but my cable company wouldn't give me a CableCARD when I changed my service, because they didn't have to.
It's completely unsurprising that the pioneer in the space lost their spot, but they absolutely could have owned the market with a bit better marketing and availability.