@Khahan having actually done playtesting about this. Running more lands in your deck can really help you beat shops. Specifically, as an Oath player, running more lands let me more effectively board in Energy Flux. That helped me win a much higher percentage of games than I had been before. (I think it was on the order of a 12% jump... I'm trying to go back and find the paper.)
Why do you think that more lands has no effect? Have you tested this theory?
Energy flux does very little against competent shops pilots, especially once ravager is out. You're talking a 3 mana enchantment with a triggered ability they can respond to. Remember, shops is just so much faster these days and ravager laughs at energy flux. By the time you get 3 mana on the board to cast it you need 4-5 mana. By the time you have that shops has you on your heels. When it triggers they tap artifact mana, sac it to ravager and use the floating mana to pay the rest. Or they just pay for ballista and 1 or 2 spheres, let the rest go the yard and finish you off.
And @ChubbyRain - yes absolutely more artifact mana can help. But only if you win the die roll or they dont have 1 of 9 sphere effects out on turn 1.
The tools are out there. Fragmentize, pithing needle, ancient grudge, hurkyls recall, rebuild, even swords to plowshares can all slow down/limit/stop shops. Some of the cards are even versatile against other match ups - fragmentize can help against oath, it can help against landstill if they play stony silence etc. Swords is pretty universal. Generic bounce like repeal can be used in multiple match ups. Pithing needle is such a staple against any BUT gush mentor its almost main deckable.
We have answers at our disposal. Adding lands just isn't going to get the job done for mentor decks, though.
It's pretty important that there are basic lands to fetch for each color. or at least and Island and a mountain/plains/forest for artifact hate. You're right that developing your board of mana one by one won't catch you up, but it helps. And as was mentioned running artifact mana makes a huge difference.
If you're on the draw and they land two spheres on turn one, sure, moxen aren't going to help. Otherwise though, you can play them for one mana a piece, or two in the case of sol ring, and develop a board.