Shutting down a new PC is not a problem and can be done on all computers if it is not used for a longer period of time! However, in rooms with high humidity, continuous operation is sometimes necessary, as the computers can be endangered by condensation!
For example, a traditional hard drive has moving parts, while a solid-state drive does not do this and is therefore far more robust. But not only turning up or turning down has an effect. Mechanical parts eventually fail, and if they are used constantly they inevitably wear out. Computers also heat up when they are on, and heat is the enemy of all components.
The idea that you shouldn't turn off your computer at night is very popular. Because frequent shutdowns and start-ups presumably affect the components and wear them out more quickly. On the flip side, the constant use of your computer also seems to add to its wear and tear.