Update from 7.14 to 8.4 in a rudimentary way

Due to the issues we are experiencing when transitioning from version 7.14 to 8.4, I am considering performing the upgrade in the following manner:

1.- Conduct a clean installation of 8.4.
2.- Compare the database structure of 7.14 and 8.4, apply the changes to the 7.14 database so that it complies with the structure of 8.14.
3.- Implement the updated database into the 8.4 version.

I see several potential problems:
1.- That as part of the version change, certain records in specific tables may need to be inserted/updated/deleted.
2.- That the project might use files in some way (in this case, they wouldn’t be transferred).

What do you think? Is it feasible?

Thanks and regards.

I wouldn’t advise that route, it’s likely much cheaper to just pay a competent PHP developer to solve the upgrade problem for you (and for the rest of the Community), and get a proper upgrade done. The manual process will turn out to be too complex, unless you have really simple data.