Consequence of not replacing an extracted molar?

consequences of not replacing missing teeth- reduced chewing function - shift / tilt of adjacent teeth in to the space of missing teeth , extrusion of opposing teeth. This will ultimately cause a shift in your bite / occlusion. Might cause issues with your bite/ tmj. - bone loss. Both in width and in height. Future implant might not be possible without re building the bone. Therefore additional surgical steps and cost.

That is not advisable. In case of not replacing the extracted tooth, neighboring teeth will migrate into the extraction space.

Not replacing a
missing tooth will cause other teeth in the mouth to shift. This may begin with
the 2 teeth adjacent to your tooth to be extracted, preventing a new implant or
bridge from being placed in the area, but creating a wide space that catches
food. Or, the tooth on the opposite arch will begin to erupt out of place in an
attempt to find its biting partner. The best recommendation is to replace your
tooth as early as possible. If necessary, as your dentist about a removable
acrylic prosthesis that can act as a tooth and retainer until you’re ready to
invest in an implant.