Disadvantages of creating custom tables NOT by extending Task table?

[Aki18]

If a custom table is created by extending Task table, all the fields of Task will be inherited to the new table. Also, newly created fields of the new custom table will be visible in Task table. On the other hand, non-extended custom table has only a few default baseline fields.

I think this kind of specifications sometimes useful, but sometimes not.

In case we would like to create new custom table NOT by extending Task table, are there any other disadvantages?　If any, please give me some examples.

Best Regards,

Aki

[Vasantharajan N · Accepted solution]

You need to build all functionality (Fields, UI / Data Policies & Client scripts, Script Include, Business Rules, etc.,) from the scratch if you are not extending the task or any other eligible existing table.