People Express was pretty bad, both versions but the 2nd one namely. 2 aircraft, one goes down for mx the other gets nailed by some GSE just a few weeks into flying, all flights cancelled, airline shuts down. Good run. California Pacific had a similar short and sad time in the sun.
Leisure Air of the mid 1990s, which was operationally based at SFO with DC-10-10s flying to Hawaii from SFO/LAX on behalf of Sun Trips and a DC-10-30 flying from SFO/LAX to AMS, STN, and a few other places, and A320s/757-200s doing trans-con flights like SFO-BOS as well as connecting quite a few cities to Mexico including DEN, ATL and I think CVG. One of my former co-workers was the ops manager for part of their short existence. The DC-10s would break all the time, it was common for the London flight to break en-route and sit at STN for days screwing up the whole schedule as it was the lone DC-10-30. Police were called to the gates at old SFO International Terminal D(T2 today) routinely, and some literal riots broke out here and there when vacations were out right cancelled. My friend recalls that the DC-10-10s, although not used on sectors much over 5 hours, had nice legroom decent seating while the DC-10-30 was packed in like sardines. While the airline was one of the first Airbus operators in the US(1994 or 1995 I think), the 2 DC-10-10s were ex-United and appeared in several different hybrid Frankenstein liveries in their short time with Leisure Air. I am told this is because they were down for heavy work so often that the company tooled around with the livery to cover patches haha.
I heard a lot of horror stories about the scheduled flights that Rich International started around that same time 1994-96 I think. The L-1011s were used on sparsely operated scheduled flights from HNL/OGG to SFO/LAX/SMF/ANC and other cities with scheduled charters popping up to more airports like SJC. I've heard stories about people showing up to the airport for the 1 weekly flight in some cases with a sign up saying "Flight is cancelled, call this number". Not a good thing to come across pre-internet! The airline also shut down with no warning leaving pax wandering the airport enraged with no one giving any direction at SFO and pax swarmed the other airline counters causing police involvement haha.
In the end of it's life, Mark Air decided to fly to as many random points across the lower 48 as possible, and they did so with a very small fleet of 737s. If I recall correctly, a 737-200 did a DCA-CVG-MDW-MSP-DEN-PHX-DEN-MSP-MDW-CVG-DCA route with 20-30 minute turns all day long! That is no room for error, imagine how often they were late for de-icing, mechanical and traffic delays, ect. They also had a few 737-300s and 737-400s all running very tight schedules, such as SAN-OAK-RNO-DEN-MCI and back with 30 minute turns. No surprise that after many successful years, the airline failed within 4 years or so of starting these flights outside Alaska and Seattle.
From my operation experience, the more an airline outsources and the lower quality the vendors, the less likely the airline is to handle IROPS in any acceptable manner. Sun Country signing bottom-feeding vendors and ditching the concept of Station Managers tells me they will make the list soon, after decades as one of my favorite carriers.