This is really veering off topic now but from 2010 to 2012 McLaren were the only team making inroads in to Red Bull in terms of car performance (they have had shortcomings in other areas though). In 2012 they were slightly ahead of Red Bull on average in terms of qualifying pace.
They haven't won many championships over the last decade or so because we've seen two very dominant periods for Schumacher and Vettel. Over that time they've been pretty consistently the second best team which frankly isn't bad and if the regulations hadn't changed in 2009 it's possible we could have had a period of McLaren dominance instead of Red Bull dominance.
If they have another two seasons like this year you can say they're a declining force but not now.
They haven't won many championships over the last decade or so because we've seen two very dominant periods for Schumacher and Vettel. Over that time they've been pretty consistently the second best team which frankly isn't bad and if the regulations hadn't changed in 2009 it's possible we could have had a period of McLaren dominance instead of Red Bull dominance.
If they have another two seasons like this year you can say they're a declining force but not now.