When can I JUST use TM internet modem as ONLY a modem, in BRIDGE mode, with NO NAT, NO firewall, and frankly NO Wifi.

Y--- Evidently, the fiber person that was in charge of "Fi"? at Google moved over to TuCows, and they are intending to go after that market.  I was studying TuCows, who got heavily into the domain name business, and has bought several companies in that space.  If you remember, they were hosting most every applications in the world many years ago.   They could become a force.  He's been fighting against Network Solutions' horrible business practices for years.  (SEE their Wikipedia article to read about just how bad they have been and still are.)  This cancel Culture must stop, and he may be a force that accelerates that effort.  (NWS and separately, GoDaddy have already decided that some companies should not exist, and ERASED them from the internet.)  I'd strongly suggest a boycott of any company that practices cancelling anyone for other than really heinous reasons.  If not, eventually they will come to erase you too, and in the mean time, you will have lost freedom of choice and speech.

It would be nice to have some new entrants into that market.   Elon Musk is also talking about putting up a ton of small satellites to provide cell and internet service, worldwide.  Just watch, to say that these leaders of today, Amazon, FB, Twit, Google et al can't be replaced hasn't been in the computer business for "very long".  Eventually, they too (most of them), will disappear as well, for hurting their customers, lousy products, or overpriced bunk.  Replace NASA?  Sure, that's impossible.  Disrupters rule, at least the great ones will, eventually.