TH8s are going to get crushed the hardest of any TH level.
The first "big" offensive jump is from TH6 to TH7, but there is nothing ridiculously expensive to upgrade as a TH6. That allows you to cap your 2M/2M resources easily in one farming session, set aside what you need for an upgrade and dump the rest into walls before logging off. Even if you forget to dump your resources and you lose 200k/200k, you can make that back in sometimes one raid.
The jump in offense from TH7 to TH8 isn't great, just an additional troop level. TH7s still don't have absurd upgrades, and you can fend off unskilled TH8 attackers (which still exist at this point in their game progress).
The next big jump in offensive power is from TH8 to TH9. 20 more troop space, another level to troops, the AQ and a 4th spell slot. TH8s now have some upgrades that hover around the 3-4M mark, so you can expect to get hit for measly gains by TH7s and average skilled TH8s, but absolutely wrecked by TH9s. Both my accounts got hit the hardest while at TH8, and that was one of the reasons I moved on to TH9 after 2.5 and 1 months on them, respectively. But farming isn't too difficult as a TH8. You face essentially zero loot penalties on any bases that are capable of having lvl 11 collectors (the max).
Don't like getting hit by TH9s? Get your splash defenses maxed, head to TH9, get the new splash defenses built, and go up to the crystal leagues where you'll get sniped all day. But prepare yourself for a substantial dropoff in your ability to farm loot.
Pick your poison.





