In your log, there appears to be entries suggesting the wrong instance of MySQL 5.7 might be running?
From my log:
{"thread":"main","class":"Process","process":"mysql","level":"warn","message":"2020-05-17T00:16:57.672253Z 0 [Note] /Users/gary/Library/Application Support/Local/lightning-services/mysql-5.7.28+4/bin/darwin/bin/mysqld (mysqld 5.7.28) starting as process 47310 ...","timestamp":"2020-05-17T00:16:57.677Z"}
{"thread":"main","class":"Process","process":"mysql","level":"warn","message":"2020-05-17T00:16:57.676444Z 0 [Warning] Setting lower_case_table_names=2 because file system for /Users/gary/Library/Application Support/Local/run/Y2t4uqnX_/mysql/data/ is case insensitive","timestamp":"2020-05-17T00:16:57.677Z"}
From yours:
{"thread":"main","class":"Process","process":"mysql","level":"warn","message":"2020-06-25T07:29:36.351560Z 0 [Note] %%userDataPath%%/lightning-services/mysql-5.7.28+4/bin/darwin/bin/mysqld (mysqld 5.7.28) starting as process 51854 ...","timestamp":"2020-06-25T07:29:36.358Z"}
{"thread":"main","class":"Process","process":"mysql","level":"warn","message":"2020-06-25T07:29:36.352806Z 0 [ERROR] Error message file '/usr/local/mysql-5.7.20-macos10.12-x86_64/share/english/errmsg.sys' had only 1086 error messages,","timestamp":"2020-06-25T07:29:36.358Z"}
{"thread":"main","class":"Process","process":"mysql","level":"warn","message":" but it should contain at least 1119 error messages.","timestamp":"2020-06-25T07:29:36.359Z"}
{"thread":"main","class":"Process","process":"mysql","level":"warn","message":" Check that the above file is the right version for this program!","timestamp":"2020-06-25T07:29:36.360Z"}
{"thread":"main","class":"Process","process":"mysql","level":"warn","message":"2020-06-25T07:29:36.355577Z 0 [Warning] Setting lower_case_table_names=2 because file system for %%site.runData%%/mysql/data/ is case insensitive","timestamp":"2020-06-25T07:29:36.360Z"}
I’m not sure why your paths aren’t being resolved fully as in my system, but I see entries indicating that you have sites running on MySQL 8.0.16, which appears to be loading correctly, so that’s probably a red herring.
In any case, I’d certainly try creating a new site and manually importing the files and database from the problematic one to see if it runs any differently.