Well, yes, you need to seal those joints there. Whatever you need to do to accomplish this is what needs to be done. Lint is not good but the moisture is the main issue.

If you now have 'a ton of lint', that isn't good for the ducting, the ducting will eventually clog. Then you might have a fire. Fix your lint filter!

No dryer filter catches 100% of the generated lint. The filter would need cleaning during the cycle, probably several times, to avoid the airflow becoming obstructed.

(Fisher & Paykel developed an auto-scraping filter with tighter mesh material for their SmartLoad dryer but it was discontinued approx 10 years ago. I have four, two in-use and two spares.)

Like Cheesecloth?

I'm not understanding where the untaped joint is.

Would it be possible to separate the vent at another joint, pull the venting up into the attic and apply the tape? Then feed it back into the room/ cabinet and reconnect where you purposely separated it?

Another possible but unorthodox solution could be to clean the lint & dust off of the vent & use the fireblock version of spray insulation to hold everything in place & prevent lint & condensation from seeping out of the vent pipe.