I SO don't even know where to start.
1) This game is a marathon, not a sprint, with a TON of RNG involved. If you are trying to run silver arena or higher with a bunch of 5* level 50 champs that you got from the campaign, it's probably not going to work. You CAN synergize with those initial champs and login rewards. And, albeit slowly, work your way up the ranks.
2) Speed boots are NOT required, but right now Speed is one of the MOST important stats in the game, getting the first turn is important, but you work around it if you have high RES/DEF/HP. After much trial and error, moderators/CC/end game players have found out what frequently works best. The game wasn't built that way, it's just the way it worked out and experienced players have learned to optimize the game to their advantage. That just takes time, and dedication. Speed is important because that what everyne does now: tries to go first, ATK up, DEF down, maybe Crit DMG up, then nuke. Not likely to get a prolonged fight in PvP. That's why Speed is important, not because of the game, but because of the players.
3) The game is what it is. The people here who give the best advice have done so after many years of playing, learning what works and what doesn't. They use the game to their advantage and offer others the advice to do the same. RNG is huge and it may take an entire day of grinding dungeons for artifacts and campaign for levelling up chickens and champs. You may only get 5 useable artifacts (SPD boots may not even be one), including upgrading (yes, even that is RNG) during that time.
4) PvP has always been a point of contention among players, generally newer players who don't have the champs to compete with someone who has been playing for a year. I don't agree with the mathcmaking style Plarium uses, but then again, I don't like PvP in general. I'm really not any good at it. I prefer to stay in PvE, but in order to progress, I needed to move out of my comfort zone.
I don't think I'm done with my rant, but I'm going to stop here