PSA health regen is busted

We currently blame lifesteal for pretty much everything, champions who are supposed to be squishy can effectively "drain tank" baron but has anyone stopped to see the values on health regen at lvl 18? the number seems fairly low but considering it ticks... who knows how, the amount of healing done through simple regeneration is incredibly strong

For the sake of this discussion, do this, enter on sandbox mode, level up to 18, don't buy anything, disable minions, run up to a turret and just attack it... admitedly I was running 0/12/18 masteries but the fact that you can simply stand there and tank a turret with NO items whatsoever is crazy, I do think turrets scale as the game goes on but I did it with baron and found the same result, I can simply stand in there and kill it with SORAKA'S autoattacks if I kept attacking for like an hour lol as soon as my health went down, my health regen healed me for 600 :S again, with NO items just base stats.

I thought it was odd because first I had spirit visage and redemption and I was like: wat but then I sold everything and was surprised at the results ._. of course, champions can hit for a lot more than what baron can and a lot quicker but this is probably the reason why a champion who is ahead can dive so effectively, turrets don't tickle, health regen is simply busted