Yes, it's another guy stuck in a fantasy world however it's a more light-hearted take on the genre. A bit lewd at times but still generally wholesome. While Konosuba doesn't take place in a video game, it captures the world of an MMORPG quite well. In a way that SAO didn't in my opinion.
Honestly? Konosuba is SAO but funnier and less serious in every single way. Literally the same plot with very minor differences, but Konosuba is casual, hilarious, and overall a great time.
SAO, is a virtual game where you use a NETGEAR. But in "Kono Subarashii Sekai ni Shukufuku wo!" you die, and you become stuck in a virtual reality game, just like SAO. They also have similar story lines in them. Their are levels, money, points, mobs(in mmos), and etc. They're are also guilds that you can join. The purpose of SAO is to beat all 100 floors. The purpose of Kono Subarashii Sekai ni Shukufuku wo! is to beat the Demon King to beat its purpose. They are common in a lot of ways, that it's hard to relate.
Both anime represent a video game world feel. Kono suba seems like the first arch in SAO I.
Konosuba does the same main-protagonist-stuck-in-a-virtual-world-that-operates-like-a-video-game story but with buckets more to offer. The characters are hilarious and they actually develop despite the short run time, the video game mechanics are believable and interesting to watch, and having the same level of quality in its animation while still being classified as a harem anime. Watch Konosuba instead.
Sword Art Online promised a personal journey dealing with death anxiety and acceptance of death in a strange world. After the first few episodes, it was clear this wasn't going to be delivered and fan service ensued. I recommend KonoSuba instead. Its more fun without the pretense.
Both of these anime are very well known, and two of the most popular anime starting in 2016. They have similaries, with one main difference, rezero focuses on a darker storyline, and konosuba focuses on comedy.
In both, a young boy is transported to a video game rpg like world, both are very well known, and enjoyable. I think someone who likes one, will enjoy the other later, but should expect a change in tone.
In sao, a boy enters a virtual reality game alongside many others, and finds that they cannot leave, and the story follows from there, as he and many other gamers try to
It is similar, as it revolves around being in another "world". However, the two anime differ in genre, as SAO is an action/adventure, whereas, Kono Saburashii Sekai ni Shukufuku wo! is both things, but primarily a comedy.
Konosuba is a game anime too
-Being stuck in a video game scenario
How they differ:
-Konosuba has a lot of comedy perhaps almost as if it was a parody of MMO games anime in general