None of the Baltic states air forces have any combat aircraft at all, Poland’s air force isn’t much larger than Ukraine’s air force, and Rumania’s is even smaller. Even if they were large enough to enforce a no-fly zone, they’d need NATO E-3 Sentry AWACS aircraft to give them the needed radar coverage to do so - NATO’s E-3s are operated by multi-national NATO aircrews and are registered in Luxemburg. The only NATO nations with air forces of sufficient size and capability to enforce a no-fly zone are the long term, Cold War members.
Keep in mind that Putin doesn’t get to retire to some dacha or the french riviera. Strongmen rule until they don’t. Natural causes, a bullet to the back of the head, or global suicide with nukes.