Does this kind of love truly exist???

People often say that yaoi is unrealistic and not even nearly close to the reality. I kinda understand that when it comes to the context, mc’s lifestyle, sex scene or so on. But there is one thing i think is can be realistic in yaoi is that the way the MCs love each other like they are willing to do everything for their partner happiness or love them regardless of gender or weaknesses or very loyal to their lover or like never care about someone trying to get their attention but their loved one ( like in http://www.mangago.me/read-manga/sayonara_game_minaduki_yuu/
http://www.mangago.me/read-manga/mods/
http://www.mangago.me/read-manga/dakaretai_otoko_ichii_ni_odosarete_
19 days
http://www.mangago.me/read-manga/mujihi_na_otoko/
http://www.mangago.me/read-manga/saezuru_tori_wa_habatakanai/
...)
It is just my personal opinion. Do you think that kind of love truly exist? ( i mean all the fictional aspects aside and focus only on the feelings towards each other of MCs). Your share, real experience and opinion means so much to me. So thank u a million in advance