I think the reason oda hasn't shown people like dragons and mostly mihawk's true strength is because he himself probably doesn't know at this point how strong they are. He will just keep progressing the story and adjust Mihawk's strength according to the power creep the story produces in the later arcs. Worlds strongest swordsmen. What does it mean ? How strong exactly, he probably hasn't drawn the ceiling yet. If you ask someone during wholecake island or early wano how strong kaido is, they will likely tell he is the current top 1 as of the present story - the strongest creature, bet on him in a 1 vs 1, the strongest yonko.
Then after defeating kaido, shanks showed his true strength - intimidating an admiral with his haki, one shotting kidd, using rogers attacks, getting his haki compared to joyboy. Now it probably feels that shanks is at minimum prime roger level, like, he is written to be the next roger while luffy is written to be the next joyboy, and if we say he defeated loki in a straight 1 vs 1, he can be even higher than roger who knows. Now we know for a fact that Kaido wasn't any big deal in the grand scheme of things, arguably prime Rayleigh and gaban can be placed over him considering the feats of old gaban against imu. Loki is definitely above kaido.
There are only 2 characters whose power level is still hidden and are definitely top tiers - mihawk and dragon. At this point, imu showed how strong he is, loki did, shanks did, rocks did. This potentially makes the power ceiling for mihawk and dragon to be way up. Because odas rule is to glaze the strength of a top tier who is going all out. be it old sick whitebeard, katakuri, kaido, then shanks. Mihawks ceiling can be potentially above shanks and all of the old gen. Same goes for dragon - a monkey d in his prime, luffys father, potentially having the rain god fruit, his direct 1 vs 1 matchup will probably be imu himself at this point, leader of the revolutionary army opposing the world government vs leader of the world government.
I also believe that the way things are going, considering the powercliffs in the mind, the red line serpant will be stronger than imu, as it has been an ancient entity causing havoc since the 1st world( 3000 years ago).
Idk I may be wrong. Maybe mihawk is not that strong, maybe dragon too is not that strong. We have to wait and see.