We talked about lifeboats last time. Yes, they have benefits - after all, they are optimized for the task. A lifeboat, made by converting a Crew Dragon, could dispense with SuperDraco engines and wouldn't need the cargo trunk. And if a lifeboat would be made from scratch, it might work without much power and radiator - using resources of the station, it might use fuel components easier to store for a long time, wouldn't need some docking capabilities - all of that makes a lifeboat simpler and cheaper to make. A lifeboat may not even need a standard docking port, using instead something simpler and cheaper, as lifeboats are supposed to stay for a long time without moving around.
Here are also some drawbacks of lifeboats. The lifeboat needs to remain in space longer than a transport spacecraft - for example, Soyuz might work for some 6-7 months, while some lifeboat projects were planned for 5 years. And that means the lifeboat may accumulate more damage from micrometeoroids and space debris while on duty on the station, which of course is dangerous. Next, lifeboat still need to perform perhaps the most delicate function of modern spaceships - return the crew safely to Earth, that means passing atmospheric plasma on the way back, keeping orientation, safely opening parachutes or landing on the runway. All the precautions to keep the crew safe should be done while designing the lifeboat - that's the majority of the cost and complexity. No wonder space agencies may choose to save the hassle and some billions in development costs; for relatively infrequent flights and short expeditions they'd still use the spaceships which are necessary anyway.
That doesn't mean the lifeboats are useless. When the conditions of spaceflight change, lifeboats suddenly may become the preferable choice. For example, if we'd have Space Shuttle today, and for some reason didn't have or use Soyuz and Crew Dragon, lifeboats would be a reasonable component to have on a space station, as the Space Shuttle can't stay in space longer than a month. Maybe when we have various commercial stations and Starships are proposed to fly people to space, lifeboats can be used as they were planned some decades ago.