To The Moon

If they can can continue expanding while maintaining neutral to positive cash flow, I think they'll do OK.
I normally pay a lot of attention to the balance sheet, but in the case of a company that, financially, is something like a REIT, balance sheets can be hard to read.
They have a lot of accumulated depreciation holding down their asset valuations while the actual value of several hundred thousand miles of active rights-of-way for fiber has more likely been appreciating.
Acquiring those rights of way, etc. would be nearly impossible, today. Certainly it would be several times the cost of a decade or two ago.
When a cost that is mostly land, or very long term rights, has been depreciated to half its original value (as seems to be the case with LUMNs balance sheet) it can lead to significant undervaluation. It could be that the plant they bought for $40B and are carrying on their books as $20B is actually worth more like $50B and that they'd get that if they offered it for sale. That would put the share value in a different light....
It's hard to say what it's worth now. The most recent sale I can find in a quick search is from when Allied Fiber sold a 700 mile fiber line back in 2016. They got $24 million in a chapter 11 liquidation. How many miles does LUMN own? 600 times as much? And it's how many years later (and how much harder to put together a national right-of-way network)?

But I also look at "goodwill" as another way of saying "we screwed up and overpaid by $$ millions when we bought X." That could be an issue for LUMN (and a lot of other companies). LUMN has close to $10B in goodwill and "other intangibles" but they also seem to have $30B more in assets than show up in their GAAP balance sheet.
It's an interesting stock. $XPeng Inc.(XPEV)$