This is the first real decision in a bathroom remodel, and it is worth spending an evening on rather than deciding on demo day.
Keep at least one tub in the house
The resale advice you have heard is roughly right, but it is often mis-stated. You do not need a tub in every bathroom. You want one somewhere in the house, particularly if the home suits families with small children. If the hall bath has a tub, converting the master to a large walk-in shower is an easy call.
Tub-to-shower conversions
Taking out an alcove tub and building a tile shower in the same footprint is one of the most common jobs we do. The plumbing is largely already where it needs to be, the footprint is fixed, and the room usually feels twice the size afterwards. It is a good-value change.
Who is using it in ten years
If this is the house you intend to stay in, plan for that now. A curbless entry, a bench and blocking in the walls for grab bars cost very little while the walls are open and are expensive to add later. Nobody has ever regretted the bench.
Be realistic about the space
A small bathroom with a huge shower and nowhere to put a towel is a worse room than a sensible shower and usable storage. We walk the space with you and talk about how you actually move through it in the morning, because that is what you live with, not the render.
