...Because they didn't do a lick of marketing.
I had a Nokia 6.2, 7.1, and 7.2 phone...and they were all fantastic. They included one management app, a few wallpapers, and a few custom ringtones...but after that, they were bone stock Android phones without all the extra gunk that Samsung adds. This is a blessing and a curse; I appreciate that they didn't attempt to reinvent the wheel, but they also had nothing notable to set them apart. The Lumia phones were at least visually unique and had solid cameras for their day, but while I appreciate Nokia showing some restraint with the shovelware, it also meant that they were slightly-cheaper Pixels.
They had a handful of other issues that make me completely unsurprised they didn't make meaningful inroads. First and foremost, they weren't sold through carriers. They were exclusively retail/aftermarket phones. I got mine at Microcenter, but that's because I made it a point to ignore any of the free-upgrade or installment-purchase offers from my carrier. Most people get their phones from the carrier; the absence of that option severely cut down their potential customer base.
AT&T also screwed over the handful of users who had them back in 2022 by mandating VoLTE, which the phones didn't support. In fairness, this also caused issues with a number of slightly-older Samsung flagships as well, but that didn't help, either.
Finally, it was ironic that most people's recollection of Nokia phones were that they were indestructible, the 7.x and 6.x phones I had scratched easily, and had screens that were more delicate than other contemporary phones at the time. To add insult to injury, there were far fewer choices for protective cases - they existed, sure, but they were almost never available retail; Otterbox only had options for a subset of Nokia phones, even for mail order.
So yeah, it's completely unsurprising that a revival of the Nokia brand didn't work out well.