You won't get a straight answer for anyone, but here's my take
Excluding touhou 3, which is like PoFV in terms of gameplay and not really comparable
LoLK is extremely difficult patterns wise but yes the game gives you an absurd amount of resources to mitigate the hard stuff and then some. Especially with Reisen and Sanae, where you hardly need to even play the game at all.
UFO is kind of similar territory, however you do have to work harder for those resources so must people consider it generally harder than LoLK although the patterns don't quite get to the same level of craziness.
DDC is also worth mentioning, it is another game that has absurd resource generation but difficult patterns to compensate. With the weaker shottypes, the game becomes easily as hard as LoLK or UFO.
SA is absolutely brutal on the lower difficulties, such as easy mode, normal mode, and hard mode, but somehow it's lunatic mode doesn't really scale up all that high. Still, it's a tough 1cc on lunatic, there are a lot of tricks you can do with the game however if you choose to seek that out.
As sort of a wild card in this argument there's also EoSD, which has some really, really hard stuff, and a rank system to boot. However, it's first three stages are pushovers, and bosses have rather squishy healthbars that get obliterated with bombs.
Here's my scrub opinions on difficulty considering all the following.
For a lunatic 1cc, any shot type goes:
UFO > EoSD > MS > SA > DDC > IN > HSiFS > PCB > LoLK > MoF > WBaWC > TD > LLS
To play perfectly (LNN):
LoLK > EoSD = UFO > other stuff im not good enough to rank