Microsoft just released upgraded Surface devices -- such as the Surface Pro 8 and Surface Go 3 -- that will include optional cellular connectivity, but those configurations aren't expected until 2022. If you can hold off until next year, these refreshed versions will offer newer hardware than their predecessors.
You can also rely on a 4G-equipped tablet. Apple provides cellular options for its iPads, whereas it currently does not for its MacBook laptops. Cellular services also promote Samsung's Galaxy Tab lineup as an Android 4G tablet solution. In either case, adding a Bluetooth keyboard and a digital stylus to a tablet could be enough to avoid buying a 4G laptop if you don't need a traditional notebook all the time.
Finally, you can give any laptop 4G connectivity by purchasing a wireless modem that connects to your USB port. While it's an external dongle instead of a built-in modem, it offers several advantages: a fairly-low price point, the opportunity to use a wider choice of cellular providers, and the ability to move the modem from one USB-equipped device to another. However, you're relying on a third-party dongle supplier, so you won't get the level of tech support you would from a PC that includes 4G as a built-in feature.