Yes indeed, these basic age-old tools are still essential for an astronomer today. Especially if you like myself have to build-up and break-down your setup for every night out.

This is not applicable to all telescope though:

• Astronomers that opted to not use a tripod and stabalized a fix mounting point in their garden or in a personal observatry wil not need a level.
• Astronomers using a Dobsonian or when using an alt-azimuth mount do not need to worry about a compass as they do not need to polar align.
• Compass and Levels are not needed if you do not have amotorized mount.

One of the very first things to do when building up your telescope is setting up the tripod such that when the telescope mount is added, the mount is pointing due north. Additionally, the tripod needs to be set perfectly level.

Compass

Setting up a tripod due north does not need to be done very precisely. When you always set up your telescope in the same spot in your garden, you know where due North is, what tree points towards it or what roof tile you should aim for.

To be honest, I use the compass in my phone to roughly understand where due North is and that is good enough as this will be fine-tuned when polar-aligning.

Level

Setting a tripod level is essential when using motorized telescope mounts. Make sure your level is wide enough to cover the entire top of the tripod and make sure to level the tripod in 2 perpendicular directions.

Some mounts have a small integrated bubble level but I personally do not appreciate them. They are too small for me to level a tripod properly. Unlike the compass, leveling a tripod needs to be done as precisely as possible.