We were in Venice last May. Stayed at the JW Marriott on it's own island for a couple of days. It was just okay.
The best place we stayed was the Hotel Dei Dogi (https://www.dahotels.com/grand-hotel-dei-dogi-venezia/). Incredible location, staff, management, and facility. It's away from the crowds (look up it's connection with the word "ghetto") but easy walk to shops, restaurants, best pizza place in the world, gelato, the municipal water taxis, the train station, and churches.
Speaking of churches - this hotel is 3 buildings away from a church few people visit even though it houses one of the largest collections of paintings by Tintoretto any where (https://en.wikipedia.org/wiki/Tintoretto) including a couple of his most famous. If you visit ask about the one that was stolen in 1969.