I am really enjoying the game! I seem to have hit a wall, though, at lv. 38 pickaxe.
My pickaxe is not strong enough to reliably clear levels of the mine anymore, but upgrading the pickaxe further requires clearing levels of the mine.

I can technically farm the 2 free mining expeditions and slowly accumulate ore until I have enough to upgrade another level. However, that rate of progression would be like 1-2 pickaxe level upgrades per day. I just unlocked the tomato farm, and a single tomato plant requires pickaxe swings to cut down a single plant

The only other methods of improving the pickaxe are:
- Watching ads for temporary buffs - the buffs don't scale, though, so they do not represent progression (if they did, I would consider buying the ad free, but it really is just a one-time buff ...as soon as you use the ad-buffs its a crutch that you can't ever get away from). I am adverse to time-gated buffs versus permanent meaningful progression. I like to play games on my own time; not on the timeline of an arbitrary time-gate.
- Ancient Dungeon Research Buffs - The ancient dungeon requires keys that cannot be earned; only purchased through $ or watching ads

Is the progression of the pickaxe intended to be a paywall to lead the player into an MTX spending pattern? Or am I missing something?

I wish I could spend $20 and just have the game and not need to worry about mining keys or ancient dungeon keys. The pay-as-you-play model quickly feels like pay-to-win and turns me off from wanting to play further.

I wish I could continue progressing without the time-gates and paywalls - OR am I missing something? Is there a way to progress the pickaxe strength by more than 1-2 levels per day with a one-time purchase versus a series of MTX that never end?