On shared hosting your competing for resources with other websites. If they are experiencing a surge in traffic your own will slow down too.
If you opt for a VPS make sure you have enough capacity to handle unexpected traffic from sources such as a successful Black Friday campaign. If you hit the limits your site will slow down or crash.
WooCommerce websites are hosted in Docker containers each with their own dedicated resources. Additional ones will automatically spin up when there is a surge in traffic is, even across servers. We call this true autoscaling.