Climbers usually climb indoors more than outdoors, especially in the winter. That's why it's really important for them to choose the right shoes for indoor climbing.
Unlike the common practice of having multiple pairs of shoes in the backpack when bouldering outdoors, climbers who go to the gym rarely bring warming up and performance shoes or even a stiff model for slab climbing and a soft one for overhangs. An experienced climber almost always knows what they want to train with, but for those who do not have years of gym climbing behind them, it is more difficult to decide what aspect of indoor climbing is important.
Beginner climbers are generally advised to choose shoes with a rigida sole and a less curved shape. This is for two main reasons: a rigid sole allows the climber to have better support during the climb. A shape that is even and not too curved works better on surfaces that aren't steep and have good places to put your feet. This will almost inevitably lead to choosing a model with a full sole, typical of symmetrical shoes, or at most a No Edge sole from La Sportiva if you want to choose a model that provides maximum sensitivity.
In fact, unlike bouldering outdoors, where we still want to prioritize precision and sensitivity with more aggressive models, indoor shoes must be comfortable. Within the "comfort" package, we must also consider lacing: there is no rule that shoes with laces are not suitable for the gym (many models designed to keep shoes on for long periods have laces), but the speed with which we can slip on and off a slipper or a shoe with Velcro has decreed an undisputed success of these models for bouldering in general. Despite this, we have some lace-up models that are specifically suitable for the gym, such as Scarpa's Vapor Lace, which represents an excellent intermediate model in terms of both rigidness and aggressiveness of the shoe.