Tea bags are just one thing that may have plastic in the bag. Think about all of the packaging that all of our food comes in. It seems that everything is in plastic, and plastic is in everything. Microplastics are in our drinking water if you use tap water without filtering it. Even if we filter it, we may still have microplastics in the water.
Water in plastic water bottles is not good, but there are many people for whom this is the source of their drinking water, purchased cases of water from a store. When I first started prepping, I had a few cases, but I don't use bottled water.
I have long hated drinking from plastic. I have no memory of ever purchasing plastic drinkware. Everything is glass or ceramic for me. There is an ick factor for me relative to food on or in plastic.
I know I have talked about it here before, but I drink water from a canning jar with straight sides, 2.5 cups, with a plastic lid with a hole in it, and a metal straw. I started this because we had a cat who was always drinking from my water glass. I keep one of these setups on my end table, beside dresser, and in my car. Actually, I keep two setups on the tables. People who have seen the set up like it. I do remember that someone said that they would be concerned about glass breakage. I think in the 6 to 8 years that I have been using this kind of set up, I have broken one jar. I take one in my overnight bag when I go housesit or traveling.