And - of course - you're probably not even paying a couple of cents less. Those couple of cents are extra profit for everyone further up the 'value chain'.
And yet you would get, on average, 0 microplastics from drinking out of plastic bottles since those are brand new bottles which have not been subject to UV degradation of any kind. They're also entering via the GI tract, which doesn't have a particularly high rate of foreign matter exchange with the blood stream.
Meanwhile you'll walk outside sipping your glass bottle and take a deep breath of tire dust from nearby cars, which is actually the primary route of exposure for microplastics to enter the body since the lungs do exchange particles with the blood stream (notably, you will also find silicates, soot and basically every other type of thing all throughout the body via lung exchange as a mechanism).