Extremely long UITextView text causing performing issues

I have an extremely (et cetera ad infinitum) textview that is lagging when typing (presumably) because of the text.

Not sure what textkit is doing under the hood but if I were building it from scratch I wouldn't need to do any calc when the user is typing. I could just would design it so each new line is like's it's own textfield so to speak. But clearly that isn't the case. Any suggestions / can someone at Apple on the textkit team reach out ? (I interviewed with someone from that team before so I know it exists lol)

Extremely long UITextView text causing performing issues
 
 
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