I'd say the blame for this lies almost totally with Iran. They fund and prop up Hamas, they arm them, they arm Hezbollah, they arm the Houthis and prop them up. Action should have been taken sooner in regards to the Houthis and we've been quite careful to strike at indirect Iranian targets and they seem emboldened that we aren't going after their forces directly. This particular mess isn't started without Iran's funding and support.
I'm not sure why Trump is even part of this discussion this far in arrears. The fact is the world seems to be catching on fire right now, and Biden is in office and war is everywhere. I'm not going to sit here and be so political to blame the Biden Administration for all of these wars, personally I don't feel there's any U.S. action that is to blame for Russia invading Ukraine. But it's odd to blame Trump for the aggression of Iranian proxies when he took the step of eliminating Soleimani when many on the left were concerned that could lead to broader conflict. Hell, at the time I was unsure, but looking back on it I think time has shown that it was proper and sent the right message. There's a balance between not provoking a larger war but striking them enough to punish bad acts so that they know there is a price to pay that is beyond what they may gain in those actions.