If you have GERD or similar you should be on a PPI, not over-the-counter antacids. I can't imagine a doctor recommending that except for mild, occasional complaints.
PPIs have their downsides, but they're the best available treatment to avoid acid damage.
PPIs do the same thing - suppress acid. That suppression of acid makes you vulnerable to bacteria like c diff. Long term use of PPIs is also linked to dementia.
Studies into the risks of using PPIs long term show all kinds of potential problems. Higher incidence of all kinds of mineral deficiencies, sometimes even life threatening. Increased risk of cancers. Increased risk of developing SIBO. Increased risk of respiratory and urinary tract infections. The list goes on.
PPIs have their downsides, but they're the best available treatment to avoid acid damage.