I've bought smartphone replacement batteries in the past, so it's not really an issue. Most popular models have alternative vendors unless the manufacturer goes

I've bought smartphone replacement batteries in the past, so it's not really an issue. Most popular models have alternative vendors unless the manufacturer goes out of their way to prevent it. Also the battery in my previous phone was at 83% of its nominal capacity 5.5 years after purchase, so I think this part is already durable enough. The way I'm cycling the battery in my current phone it could last 8 years before it reaches that level.