Roughly 1 week of mining about 6-7 hours (more some days) per day.
Mined about 35k-ish (approximately) ore per character.
Each character did around 3k mining points on their pickaxe.
Let's assume an average of 3 hours per day of mining someone can allocate.
It would take about 15 days for someone to collect 3k mining points - 5 days for 1k points.
Pick +0 > +1 - 600 points - approx. 2 days.
Pick +1 > +2 - 1200 points - approx. 6 days.
Pick +2 > +3 - 2400 points - approx. 12 days.
Pick +3 > +4 - 4800 points - approx. 24 days.
Pick +4 > +5 - 9600 points - approx. 38 days.
Pick +5 > +6 - 19200 points - approx. 76 days.
Pick +6 > +7 - 38400 points - approx. 152 days.
Approximately 310 days to get to mine beta ores.
Approximately 158 days to get to mine Heaven's Tear.
I'd understand this time investment if it was applied only to Overcharged Ores. You want to have 4% more pierce on your HTN? Sure, if you wanna mix-max, you gotta invest the time.
But 152 consecutive days of 3 hours of mining, every single day, not taking into account Pickaxe upgrade fails, the time to buy/farm stones for what ores you mine, and the actual time to play the game. Imagine every hour of play for the next half a year you'd have your other character able to farm (Farm Block System) searching for ores.
I'm sorry, but I already have a job and would probably have more fun if I took another part-time one or find an actually enjoyable hobby. I don't even want to imagine how lengthy this process would be if you just liked mining casually every now and then. Of course, this is from the perspective of someone that enjoyed mining for their own ores and selling the excess - which is the intended purpose of mining. Right now it looks like World of Mining 2 - a core game system, at least from the time-investment POV.
I'd probably make a name for myself in high-end gameplay with that time-investment, but that's unlikely - but I'd still get somewhere higher than just being able to mine Heaven's Tear or Beta ores.
I don't know how this got pushed to live honestly. I don't want to even consider the options and possibilities.
Good luck. It was a good run.