A huge problem if you use cloud infrastructure features offered by AWS, azure, vercel etc is also vendor lock in. Suddenly your site/service only works on that specific platform.
What happens if they have a failure, decide to ban you, raise prices?
I'm a huge believer in being able to move your entire service to new servers with x minutes of downtime + dns. It should be completely automated and tested monthly.
Eventually when a big player has a really bad failure or hack etc, a lot more people will be believers too. Too many people think google, azure, aws can't be hacked or ransomwared. Just hasn't happened...yet.