All US airlines are very safe. That's literally about the only thing Frontier arguably has done well. They are otherwise a bad airline. Other than being able to exploit their status matches and buy very cheap tickets, I can't really say anything else good about them (even though I wish I could since they've given me many very cheap flights).

I dunno... I fly Frontier A LOT, and consider their percentage of delayed flights very low. I also occasionally fly Spirit, Southwest, Aeromexico and occasionally AA, and all of them--at least in my experience--have been delayed or even cancelled far more often. It's a much smaller sample size, but 100% of the AA flights I've been on, about 40% of the Sprit flights and maybe 25% of the Southwest flights have been delayed by an hour or more.

And don't even get me started on Allegiant... LOL

This kept popping up in my feed so i clicked on it:

Taking Frontier's IT team waaaaay too long to figure out if they can integrate Spirit's routes... :P

They often don't sell tickets as far forward as you'd think they would. I guess their route network is too volatile to do so.

I kind of suspect their IT "team" is just one guy.

FWIW flights are available through May 20 now. Still doesn't help the guy in the video looking to book a memorial day flight!

This is interesting and I took a screenshot of it from the referenced Youtube video. Yeah F9 is one of 3 in the red but I didnt realize Jetblue was in the same area. I am surprised by Allegiant.

Unless Americans start taking a liking to the ultra low cost carrier product, Frontier will eventually go broke. In no universe do I think these guys could successfully pivot to a higher service product.

They've been floating the prospect of adding "first class" for a while now, and it's expected to appear later this year. Americans buy heavily into branding, and if they can get "first class" at a lower price point than on the legacy carriers, I can see a lot of demand for it. That experience could be a gateway for some to become F9 loyalists, or at least fly them more often.

How does Allegiant do so well? I have never flown them but my experience with my mother using them a few times in Florida years ago was that it was very similar to the Spirit And Frontier model:

Cheap fare
Everything is extra
alternate airports, like RFD in Chicago, some small airport north of Orlando that's starts with an "S" that I can't remember right now. Spirit and Frontier seemed to move away from this alternative airport thing.
Fares cheaper if you buy at the airport

All three were about hiding all the extras so they can advertise say $19 fare.

Orlando-Sanford (SFB)

Allegiant technically has a loyalty program, but not like Spirit or Frontier. Every person you see on Allegiant with a bag paid for that bag, every person paid for their snacks or beverage, etc. On F9, Gold and above get free carry-ons; on Spirit, Gold and above gets a free snack and drink. Allegiant charges (a lot) for all of that, with no way around it.

Allegiant is also meticulous about keeping their costs low. Once upon a time, I flew them frequently SFB-TRI because they were the only direct flight between those two airports. Their reliability was so bad that I would make dinner plans at the same time as my flight was scheduled because I KNEW it would be delayed... and I never once missed a flight because of it. And if you asked Allegiant for any sort of compensation, the answer was basically that you eventually got where you were going and if you wanted more you could go kick rocks. LOL

That, and flying old retired AA MD-80s until they literally fell apart is probably how Allegiant did so well.

Allegiant serves a lot of captive routes from smaller markets (with no non-stop competition) and they do an excellent job of selling vacation packages and ancillary items. They are very careful when acquiring aircraft and have a mix of newer and older aircraft to support their fleet needs. Their charter program is also very lucrative and allows them to only fly scheduled flights on days when the flights will be profitable.

Don't forget the normal 28-29 inch seat pitch, which allows 190 passengers in a MAX8, or up to 186 in an A320.

That's the same density as Frontier or just about any other ULCC around the world (Spirit with the Big Front Seats is a notable exception).