A very serious issue. Noting
also those who's native tongue isn't English - isn't even the same character set. I have struggled to help a passenger at Melksham Station with Chinese characters for station names on his phone, and to this day I'm helping people with the structure of their letters as they write English. And these are bright people.
And for those of us who reed and right the kweenz Ingish - to what level? Big words, long sentences, rare words - things need to be written for their audience. From
https://readabilityformulas.com/freetests/six-readability-formulas.php on a post here.
Readability Consensus
Based on (7) readability formulas, we have scored your text:
Grade Level: 12
Reading Level: fairly difficult to read.
Reader's Age: 17-18 yrs. old (Twelfth graders)
Fine for the Coffee Shop - probably not so good for platform signage at Piling or wherever.