The first dilemma you will get when starting Honkai Star Rail will be regarding the platform to use. This has been caused by miHoYo choosing to simultaneously make the game available on mobile devices and PCs. A PlayStation port is also in development, but not much is known about it at this point. If you're playing the game currently, the choice will be between your portable handheld device or your PC.
While there's no core gameplay difference between platforms, it's essential to understand the pros and cons of each device. It's easier to manage Honkai Star Rail on multiple devices due to the facility of cross-save. If you're using the same account to play, you will retain all your in-game progress when jumping across different devices. However, both platforms have advantages you must consider before making a final choice.
Playing Honkai Star Rail on PCs is more beneficial.
When Honkai Star Rail was announced for the first time, it was widely expected that the game would release with a PC port. Developers miHoYo did the same with their earlier success Genshin Impact, which doesn't require PC players to use an emulator. While playing on a PC seems advantageous, there are a few areas where using mobiles is beneficial.
For starters, it's perfect for those who must travel a lot. There's no energy system as such in Honkai Star Rail, so you can have the freedom to play for as long as you want at a stretch. However, it's easy to open the game on your phone and play when you want.
Moreover, miHoYo has developed its game keeping the mass audience in mind. Running the game in optimal settings will require decent hardware, but you can tweak the settings to make it easier for your phones. You can also bear a small number of lags since, unlike Genshin Impact, you won't have to aim at an enemy in real-time.
Secondly, the notifications help ensure you don't miss essential daily activities. You need to farm plenty of in-game content regularly to ensure steady progression. Mobile phones are perfect for short and quick gaming sessions.
However, there are some huge advantages you will find by playing Honkai Star Rail on a PC. First, your PC hardware is sufficient to run the game on playable settings. The official specifications aren't very high, and you don't need a gaming rig per-se to run it efficiently.
The larger screen will be helpful for you to enjoy the aesthetics and world design of miHoYo. Everything looks better on the bigger screen, from the animations of the Ultimate Team to the character art.
You then have the advantage of using physical keyboards that are more consistent. You can even choose from various controllers that work with the game. Controller support isn't yet available on mobile devices as of writing, so this is another considerable merit of playing the game on your PC.
Honkai Star Rail feels like any other single-player game due to the lack of an energy system. You can easily play it before leaving home or after coming back, and not playing in the middle isn't going to set you back on your progression.
Genshin Impact, despite being available on mobile devices, runs a lot better on PCs and PlayStation consoles. It feels the same for Honkai Star Rail as of writing. Future advancements could change the situation, but a PC will be your best bet if you have to choose right now.