Why shouldn't your base salary just reflect your responsibilities? Why need bonuses at all?
Unless your role is individual to you, which is highly unlikely in today's work environment to cover and segmented duties. HR and hiring managers won't setup an employee profile just for a member of staff.
There are things like market value that would in a person's contract but most people's contracts will not go in to the fine details of staff's BAU tasks.
I worked at one place where we could apply for an enhanced raise per year and a board approves it based on your performace. The catch was that you could only apply for it twice forever.
I got it two years in a role and then left... lol
Where I'm currently working, there's a business grade.. which is really down to legal responsibilities. How what you do can affect the company business and legal wise
and a techinical grade which is down to how techincal they deem your role is/how hard is it to replace you with someone else, the market rate of the job.
The pay is worked out on a venn diagram of sorts based on those two grades and you will get paid in the scope of the cross over area.
It's pretty cool for me as pay does reflect anti bribery policy and the fact that most of my team mates that are in the UK are based in London, so I get the "London" bonus without having to live there.
There's serveal of us with the same "official" role, but the person logged into a global server all day isn't expecting the same pay as the person is telling users to remote their computers, or the person designing and setting up solutions to world wide MIMs.