@EmperorKinyagi I think from this point on matchups will matter the most since Luffy reached this stage. Against Kaido he needed hard hitting attacks to finish him. Against Kizaru he would need to employ his CoO as well as fast hitting attacks. Against Akainu he would need to employ his FS and barrier haki to minimize contact with the magma. Against BB who will nullify his fruit he will have to hone and rely on his haki the most,etc.
That means that enemies dont need to be much stronger if at all then the previous one while still providing a threat or challenge.
Bear in mind that Oda introduced both Yonko/Admirals/Mihawk as a bundle often times when he portray them and they were introduced as the ceiling of the OP world (bar unknowns like Imu) so once Luffy reached this ceiling and around it he doesnt really need huge increases in power from now on for fights to remain challenging as I explained above.
This doesnt make sense narratively either and Yonko/Admirals have always been portrayed as mirrors to each other.