Reasons for creating linking tables?

Good day all

I would like to get the point of view from you guys out there who
has had a lot of database experience.

While busy looking into a database that have a lot of issues I have
found the following scenario :

- Let's call the 3 tables in question tables a,b & c.
- Currently table a has got a FK referencing table b
- table b contains only 1 field called id which is the PK and
also a FK referencing table c
- table c is once again a table with a couple of fields.

My question on this is, why create the linking table?

Surely the linking table can be removed and the data referenced
directly between tables a & c?

Is there a specific reason why this would need to be done?

Regards
Machiel