Defensive buffs of some sort need to stay in place unless new or old mechanics are introduced to give both sides breathing room, or else you create a meta where its rush or be rushed and the round ends in 20 mins on touchdown.
Marine req has NOT been buffed overtime; id wager with nerfs to free stuff you get, buying more items making it so you have to pay more per purchase of the same item, and metal + plasteel itself being less worth it overall economically (as its much weaker now than it was ages ago, especially since you need to upgrade metal cades to make them worth anything which means spending more metal that you do not have) means that the only time you see a decent amount of cade lines that are worth defending is in the FOB.
The reason why the game is not offensive is because of legitimate fearRP by both sides; marines being killed and not recovered, or dragged off by a caste and then put in hive with no chance of escape aka perma dead, while xenos have 1 life essentially most rounds unless the hive focuses on caps and then you MIGHT, MIGHT get ONE respawn since there’s 20 other people queing for xeno.
This fearRP manifests in holding FOB where you have lots of supplies + cades to defib safely in + Mortar and CAS support to wipe xeno structures, and xenos cave hugging where they have built in impenetrable walls that OB cannot wipe such as LV tunnels, no Mortar or CAS to worry about, and hive is nearby so capping is easy.
Thats why I stated both marine req needs a buff + xeno larvae passive and active gain needs to go up, so that both sides take more risks, otherwise if both sides are equally matched the most optimal strategy is the most passive and pussy strategy of waiting for the other side to push you.
TL;DR the current meta is WW-1 trench warefare; whoever pushes your trench first loses unless they push in fast, hard, and win in 5 minutes.