Bisphenol-A is very inexpensive for its considerable formula weight - from benzene, propylene, air, acid; acetone (or other ketone or aldehyde) and acid.
1) Polycarbonate, as above. If you don't like HCl, dimethyl carbonate will do.
2) Epoxy resin, by bis-etherifying with glycidyl chloride. That is a huge market, including paints and coatings.
3) Bis-etherify with propargyl chloride. That thermally B-stages (removes the shrinkage upon cure) then thermosets to an astounding thermally resistant super-crosslinked resin that adheres to any polar surface.
4) Bis-esterify with methacrylic acid to get into heavily cross-linked free radical or UV cures.
5) And if you really want something resistant, instead of acetone use fluorenone or a 2,7-disubstituted fluorenone. Or be fiendishly clever and use 4,4'-dihydroxybenzophenone instead of acetone. Now there is a tetrahedral tecton for synthesis!
Bisphenol-A is a claimed endrocrine disruptor. Eastman Kodak has immense production capacity for acetic anhydride (cellulose acetate photographic film). It offshot into ketene dimer chemistry then mixed cis- and trans-2,2,4,4-tetramethyl-1,3-cyclobutanediol as a BPA replacement. If you do not mind paying more and getting less, stuff as well as performance, the problem is solved.