If you look purely at convenient season-by-season records, he looks to have done OK from 2005/06 to 2007/08, but in reality, he did nothing of the sort. He played one brilliant, gutsy knock right at the end of 2007/08 to, in all likelihood, save his career (he might well never have played again but for that knock) but he'd been dreadful previously. In 2006, too, he cashed-in against the third-rate Pakistanis and failed against the quality Lankans.
So, in essence, between 2005/06 and 2007/08, he enjoyed 1 good series (against a bowling-attack missing 3, maybe even 4, first-choice players) out of 8. That, to me, demonstrates that something was clearly wrong - and having watched all the games, it was apparent what, too; he just could not drive the ball off the front-foot through the off-side effectively and edged into the slips time and again.
As for Atherton and Hussain, well Atherton's career essentially spanned 1990-2001 (he had a bad year at the end like so many) and in that time he only had 1 disappointing period when fully fit, that being the 1997 Ashes and the 1998 WI tour. Hussain, of course, infamously could barely buy a run between January 2000 and March 2001, but apart from that he was consistency personnified from his establishment in 1996 to retirement at the start of 2004.
To me, both of those are far more impressive than what Strauss has, so far, done - but I reiterate, I do believe Strauss has it in him to play as well as he has since summer 2008 for a good while longer yet. Comparing a player whose career still has a fair way to run with one whose career has finished is rarely a particularly good idea.