Your understanding is mostly correct, but not entirely. There are two "ventless" dryers, the heat-pump type and the condenser type. I venture to guess that almost all NAT members grew up in detached housing, so a vent to outside was simple. But imagine someone living in an apartment. It might be impossible to vent to the exterior, so the condenser-type dryer collects the moisture and either deposits it in a tank to be emptied periodically or is plumbed to a drain. In that respect, it's the same as your machine. I could also scold you about wasting that condensate. It is gray water that can be easily collected and re-used to flush a toilet or water garden plants. Are you really doing all you can to "save the planet"?

I watched the video you linked, and I have some reservations:
1. I'm always skeptical of YouTube creators who promote a particular brand or type of machine- he does both. Are his opinions motivated by sponsorships? I've heard of Matt, but don't follow his content regularly. What struck me in particular is the way in which he presents a vented dryer at its worst and the heat-pump type at its best- a definite red flag.

2. He completely (conveniently?) neglects to mention the condenser-type machine which does not exhaust heat to the outside. Why did he do that?

3. He talks as if the vented dryer is the only household machine pushing conditioned air out of the house. Does his kitchen not have an exhaust hood over the cooktop? Do his (probably many) bathrooms not have exhaust fans?

4. He does not consider the lifetime cost of this type of machine. Firstly, they seem as if their useful life will be much shorter, because they are not economically repairable. He claims to be- and perhaps he is- fastidious about regularly cleaning the consenser. How many owners will really do that? Secondly, typical vented or condenser dryers, when they have reached the end of their useful life, can be crushed and recycled as so much scrap steel. What of the sophisticated systems and chemicals in the heat-pump types? I find it very similar to electric cars. Those who want to mandate these "energy efficient" wonders are not looking at the total picture, IMHO.