Then we must define challenging differently. Because the long rest RAW and Leomund's Tiny Hut prevents the game from being challenging. Which is why I house ruled both. For me, challenging is risk of character death which forces the players to actually think things through and plan and use their resources wisely rather than blindly charge into every fight and burning every resource possible to make every fight a steamroll. RAW long rests and LTH utterly remove that risk except for edge cases. My players did basically the same thing every time. Get into one fight, find a place they can secure for 11 minutes, ritual cast LTH, take a long rest in perfect safety, lather rinse repeat. Whatever timers I put in they ignored. Whatever enemies I put at the door when the LTH ends, they complained and quit. Anything I did to break that pattern, they complained and quit. House ruled long rests, players complained and quit. Banned LTH, players complained and quit. Every version of "hey, could you not" was met with "it's legally allowed as per RAW, so LOL." So I house ruled...players complained and quit.
The players I've had in 5E do not want challenge. They want LOL easy mode. I'm not interested in that. I make that known. The players seem to not grok that and agree to play anyway...then cheese everything they can. This is not my experience with one group of 4-5 players. It's my experience with literally every single 5E group I've played or run with in the last decade. I've burned through well north of 200 players in total trying to find one that doesn't want to cheese everything and just LOL win all the time. Still haven't found a single one. Statistically insignificant compared to the whole community, granted, but not insignificant to me. My recently ended West Marches game had, at its peak, 37 players. Every. Single. Player. Cheesed every single thing they could to make the game as non-challenging as possible. Anything I did to prevent cheese was met with complaints and rage quits.
I did similar. A few times. I got yelled at and players quit. They didn't learn anything. I did. I learned to not run 5E.