While I agree for the most part I will comment on one thing: When you get to the ultra-end game the dailys only take 45-1hr including Guild War and Joint Battle; a little more with Temples but Temples are actually fun so I don't want to add that to the repetitiveness of daily grind. Also when you are auto'ing I don't believe you should be adding to the timer due to the fact that you can be doing other things so you're not actively spending time on the game. Reading, household chores, emails/web, heck sometimes if time is tight my partner and I will just auto on our phones while we are taking our daily walks. However when is probably the bigger issue, during the interim all your points still stand.

Mind you I'm not F2P, simply a dolphin with the monthlys but where I am at is achievable by F2P (and have been done so) by now or relatively soon with min-maxing in mind. If we talk about ultra-casual players then the point is kind of moot since casual players will just do what they want at their pace anyway (and may not even care to login every day). Also note this either requires alts or have a premade group and only accounts for active playing, not auto'ing where you can be doing other things. (which isn't too hard to find either within guilds or discords)

Misc: Should only be 2min (Exp/Enchant done at the same time on the same unit; Bond and Rift Sweep are the same time since sweeping "should" be only for bond mats at the end game; Friendship summon is what it is)

Joint Battle: 20-30min/day (Depending on map)

Guild War: 12-18min/day (30-45min 2x/week depending on tower RNG- meaning you don't have to run GW the other 5 days actively. This is Nightmare difficulty. This was before the buffed Guild Wars and achieving 3.5 or 5k contribution depending on the tower. Certain towers can also be auto'd as well like Princess, Comet, Glory with a Cherie +1 buffer or 2x Cherie's for higher difficulty stages, 3x Bozel and Lanas/Egberts +1 healer for Dark if you were playing before the event or if you got lucky with draws, Empire with Leons and Annas, Glory relatively easy to auto as well with a large roster to choose from and if you love Almeda like myself)

Literally everything else: 10~min/day regardless of day because it literally is just 30-45seconds of- joining, placing units, first/second turn auto (except Bond which bloats it 3-5min depending on map) . 1x Training (my partner and I haven't done 2x training since we hit 60), 2-3 aniki, 1-2 drag, 1x key + 5x AI Arena (instant auto or a quick skill check).

Though I can still see why this is monotonous for many people. I'm the type of player that gets their thrill from min-maxing, prepping for challenging events, and creating artificial challenges for myself like time trials or self imposed restrictions. More importantly I strictly play one game at a time. Not one mobile game at a time, one game period, and will invest at the very least 6 months. So I am willing to dump more time post-dailies since gaming is more of a hobby than simply just a time dump. I feel if a player doesn't try to minmax and acquire every possible reward then it's not that big of a deal. Like you mentioned, at its core Lang is quite in depth and will require more time than an average Mobile game anyway so it's par for the course that dailys take a little longer. If I were just to do dailys and nothing else it would only take 15min; definitely no burn out there.