You used to be able to win stacks vs bad players much more often with stuff like trips and low end straights and low flushes, thus you could coldcall a lot.
Then people started squeezing often, which hurt the profitability of coldcalling to the point of making coldcalling non existent in tag on tag games.
Then people started coldcalling strong hands and they won lots of big pots vs the guys that squeezed too much.
Now the squeezing is much more precise by necessity; if I loosen up my squeeze range, it's on the margin* because the threat of counter exploitation is very real in the modern game. Coldcalling ranges have also become more precise by necessity. Knowing where the bottom of your 3bet range meets the top of your coldcalling range is important because the looser you go with the 3bets, the weaker your available coldcalling range becomes. So vs a maniac in the cutoff? I'm literally never coldcalling because 3 betting more and more hands leads to a very narrow and exploitable range for coldcalling.
*for example, if I think 3 betting 88 vs a 3x raise from two off the button + a coldcaller is standard and correct given the opener's range and the blind's tendencies? Then if the blinds are tight or if the 3 bettor is loosening up, then I'll expand my 3 bet range to include 77, but not 66.
Ok, so what do I coldcall and how do I decide on which hands to fold?
My favorite tables to play at are those that allow me to coldcall a lot. This type of table will feature very few 3 bets to my left and a loose aggressive player to my right. Too bad we can't always find this table. Usually the lineup looks like this:
utg6max: tag
HJ: tag
me: cutoff
button tag
small blind tight tag
big blind: lag
and we're hopefully shooting the **** about some random bs when this happens:
folds to HJ raises 3x, I coldcall, button calls, small blind folds, big blind calls.
4way for 12.5bb with 97bb behind.
I like these ranges for myself and the HJ
HJ: 22+, A2s+, A9o+, A5o, K8s, KJo, Q9s+, QJo, J9s+, T9s, 98s, 87s.
me: 55-88, ATs, A9s, AQo, AJo, KTs+, KQo, Q9s+, JTs, T9s.
I think the important part is that (55-88, A9s+, AJo+, KJs+, KQo) are more profitable as a call than as a 3 bet; if you choose to 3 bet these hands for whatever reason in this spot? Your calling range ev will drop drastically not just because of the raw equity, but because good players will read you easily.
That's just what I've become accustomed to over the years.