Why did the Brits go with Tornado as a fighter??

Why did the RAF convert the Tornado and use it as their main air-defence fighter? it’s a bomber wearing a different hat.Big and clumsy.
You think a Tornado would have a hope against a MiG-29 in a dogfight? no way.
Maybe they should have used it as an interceptor,like the Russians use the MiG-31,and got themselves a real fighter,like the F-16(although they probably didnt want to buy American)
It’s a good thing the Eurofighter is coming in soon!
By the way,when the Eurofighter does come in,what are they doing with their Tornado fighters? Converting them to bombers,leasing them,selling them,scrapping them,what?