I've been thinking there aren't many real quality center forwards as the focal points left in today's football (depending on your scale for rating players).personally I cant get passed 4 once i'm thinking about it. Is it the case of simply not having many quality players recently or the modern forwards with ability all across the attacking department? and finally does a team  necessarily need a classic center forward to succeed in Champions league?

No, Look at Barca. They did it with Messi as their 'center forward'.

no is the answer
to win the champions league you need just need dedication and skill.
Pele, maradona, messi all forwards and known legends were below average heights and they had no problems succeeding.

although if your a regulation team or below middle of the table team it is suggested you do the usual tall strong target man to try and get a point here and there.

I somehow could not understand relation between having a tall striker and CL.

CL is anyways a space where one plays with the top clubs across the Europe. Having a central tall striker can have benefit of taking a good header when one take free kick / corner kick. There are other things which comes into picture.

This header thing is overrated. Zlatan scores 3-4 headers in a season. You will not buy a tall forward for only 3-4 goals in a season. CR scored 52 headers in 14 years(2001-2014). Its about 3-4 headers per season. If tall forwards score 90% of their goals with foot then who needs their height?
You need their skills not height. If you buy tall forward for scoring headers then its a waste of money

Messi also scores 2-3 headers per season with 169 cm height. So its all about positioning not height. If he didnt take corners and stayed in the box he would have even more headers. I think height is important for defense.They are more skilled headers than forwards because they head the ball 20-30 times in a match. For attack being short is the best and barcelona proved it with winning 2 cl and 6 la liga, being in cl semifinals 5 years in a row

If you are an average team, manager will save you not headers

I bump into this thread of mine to say after watching Cl final, i believe its necessary for a team to have a box striker i didnt say a center forward because many people in here think like fifa game and use cf as in 4-2-3-1 in fifa13 and before, point is i watched morata more as a box striker made better use of his time than benz( benz wasnt fully fit) but im not here to compare players and say who is better), bottom line is I think a team needs that box striker.

I saw Messi in this thread and i have to apologies i had to add non Tiki-Taka teams or better way is non possession based team. I don't have slightest of interest in possession football

Not really. I mean we won the CL with Benzema and he isn't a pure box striker nor is he extremely tall. Lewandowski isn't either and Dortmund got to the final.

It all depends on how the system of the teams works of course. Bayern did it with Mandzukic, not due to his goals but how he holds up the ball and bring others into play. There's no one way to play football. Mobile and short or tall and strong, they both work. However, tall forwards are coming back into style though as teams are getting better at 'parking bus' and tall forwards are crucial to break that down.