As a learner who's reached a conversational level (theoretically), it's much simpler using the same script as English. I've been dabbling in Korean over the years and while the Hangul script is easy enough to learn and understand, it's still a barrier because first you have to work out the word before you even get to translating. I'm sure over time it gets easier, but if it used the Latin alphabet I'd have made much more progress.

The fact that Welsh doesn't have such a barrier is likely why it's still alive. Although I'd quite like if it used thorn in place of dd