there is definitely a lot to sift through when it comes to metal. add to the fact that metal is over 4 decades old, had fractured into many, many subgenres, regional styles, etc. the thing to understand about metal is how international it is. outsiders really dont understand or appreciate these complexities. they pass judgement after only hearing a handful of mainstream-ish songs. i know when people decide that metal sucks after hearing a couple of post-puppets metallica songs, and **** like that can only result facepalms from metalheads in general. but really its the same problem i have with getting into classical. theres just so much material to cover before you find something you can actually get into. getting into new stuff takes some effort on behalf of the listener. and many dont want to put any effort into it at all, and listens to what their friends do, or whats on the radio, on tv, in movies, etc.
i cant say i like all metal. not to into power metal, never could stay with thrash (i listened to thrash almost exclusively early on before i discovered black metal), death metal didnt hold my attention at all, and progressive stuff has too much wankery. doom metal has its appeal still, i can listen to early (and dio era of course) black sabbath all day, and candlemass is ****ing badass. doom kinda has a sound heavily inspired by blues. deep bass, slower tempo, usually clean vox. some newer doom has death or black metal style vocals, sometimes beauty and beast **** but i perfer the clean vocal style in this genre. black metal is king for me, but usually the early norwegian scene or first wave stuff (like hellhammer/celtic frost, mercyful fate, venom, bathory, etc), of course norway puts out tonnes of good bm bands, some stuff from sweeden too (marduk, dissection). viking and folk metal as i mentioned earlier, which has a rather diverse performance styles and often regional sound (for example primordial is irish and so has a celtic sound and themes, local mythos, etc). there is also stuff you cant classify, like arcturus. but it really takes some digging to find what you like.