Often true. OTOH, the reduced footprint (vs. either 1 articulated or 2 normal busses) can speeds things up, especially on cramped and congested city streets. And if you're getting near gridlock-level congestion, the length of the articulated busses can be like dumping gravel into your system's gearbox.
cant they just put another entry door?
My local transit agency just stopped allowing rear door boarding, and that was one of the main reasons: https://waypointblog.com/capmetro-is-ending-rear-door-boardi...
People want to get to work on time after all. Entering and leaving the tram or bus through all door is a simple way to improve public transports reliability.