Nothing really definitive happened in 2005, it’s just that it was the year when I realized that all the contemporary bands just weren’t all that great or interesting, and a lot of older bands had begun to decline as well. I blame this a lot on the internet and social media and its influence over people and what they listen to, the types of music that get attention and the way its made. It’s just different, and not in a good way.
I’m a huge metal fan, and as of right now the one band that I can think of who as of 2018 hasn’t disappointed is 1349. For the most part up until now they’ve kept it real, mainly courtesy of Frost (legendary black metal drummer of Satyricon, ex-Gorgoroth, many others) and they’re the only live act I’ve been really dying to see over the last several years. Metal in my opinion isn’t in as bad of a shape as a lot of other genres of music - at least the ones that actually require musicianship and feature real humans playing real instruments - because there are still influential bands in Europe, but I feel in North America we’re just stuck with (pardon me) indie hipster drivel and electronic computer-generated garbage, and really not much else.
I believe the best music was made somewhere between the early 70s - late 90s, or if we want to separate by genre, perhaps the best hard rock or punk rock in the 70s, and the best metal from around 1982 - 1997 or so. I don’t care about new things either; I’m not so sure it’s really much to do with getting old, at least for me, as it is that I share very little in common with this generation. I personally despise the plastic sounding, ultra-compressed, over-produced mess that is almost every single album recorded in the last decade. I want to hear the guitar(s) and the bass and the drums all separately, not a garbled wall of sound with 50 different tracks layered on top of the whole damn thing.
I don’t know what music you might like or if you have any affinity for metal at all, but if you might be interested, you might want to give Fenriz (Darkthrone’s drummer if you’re unfamiliar) a listen. He does a podcast on Sound Cloud I think once a month, and he plays a lot of contemporary underground stuff, mostly newer European metal but sometimes other stuff as well. I still can’t say anything I’ve heard comes even near to the old 80s and 90s metal bands I listen to regularly in terms of quality or originality, but you might hear something you like. That, and Fenriz himself is always entertaining.