first of all, when building a venue for a sporting event on any kind, you want the fans as close to the action as possible: in short, this didn't happen, the fans were quite far from the players as you can observe here ( https://esports.gg/_next/image/?url=https%3A%2F%2Fadmin.esports.gg%2Fwp-content%2Fuploads%2F2023%2F02%2FFPX-vs-KC-at-LOCKIN-on-stage-968x544.jpg&w=750&q=75 ; as opposed, for example to a basket stadium, https://static01.nyt.com/images/2023/02/03/multimedia/00nba-lebron-impact-02-twgl/00nba-lebron-impact-02-twgl-videoSixteenByNine3000.jpg ), that is not a tragic problem, but it is going to make the fans look like a completely different entity from what's going on in the game; me honestly i would've suggested a glass divider, kinda like the artemio franchi has ( https://www.dolcelunafirenze.com/images/stadio.jpg ), totally doable; also the fans need a place to hang their banners, which were just not there.
secondly, i'd point out that, if the accusations are true, the treatment of the fans visiting was shocking. i've seen a thread calling out the organizers for not allowing bags, waters etc; that thread also said they had no ac inside. i honestly find it hard to believe an event can be organized so badly, i've been working in a stadium for a while and i know fully well that is not how you treat fans. but i didn't actually go to sao paolo, so i won't elaborate further.
but the most important thing that needs to change, imho, is how these fans are organized, let me make this more clear: the stadium can't just be silent, but it can't be messy either, the crowd need a direction while chanting ( the fans chanting against other teams' players is totally normal and whilst it shouldn't be glorified it should be accepted as a part of sports ), if an organized group won't form the event organizers should've gotten involved in some way; seeing a game like ( https://www.vlr.gg/167359/evil-geniuses-vs-talon-esports-champions-tour-2023-lock-in-s-o-paulo-alpha-qf ) with a half empty crowd is pretty sad. for some context, here are the best fans itw at a normal game ( https://i0.wp.com/www.sportpeople.net/wp-content/uploads/2020/01/Milan-Udinese-5.jpg?resize=1140%2C641&ssl=1 ) ; as opposed to the lockin crowd at its best, ( https://www.thespike.gg/_next/image?url=https%3A%2F%2Fcdn.thespike.gg%2FOnur%252Fvalorant%2520lock%2520in%25202023%2520fnatic_1677978063666.jpg&w=1920&q=75 ), this is obviously not what riot should aim for, it is not feasible, the grandfinal didn't look bad fan-wise, but every game should've been on that note, stupid little white plastic sticks are not enough.
in conclusion, watching any sporting event live should be in primis an enjoyable experience, before wanting to see their team, the fans should be there for the experience, i believe riot failed in this regard and the event would've seen a huge benefit from a more thought out organization, just my opinion.