Whilst I’m glad to see WG do a video explaining the high end consumables, anything to provide help/tuition for new or and/or existing players is to be applauded...
It’s WG so the video presents them as some sort of silver bullet to make you invincible on the battlefield, it’s cynical marketing to drain your credits at high tiers to get you to spend cash...
To be fair they do mention the down-side and show the negative impact of trading a repair kit for reactive armour, use that example, think about what will happen if you can’t use your mega expensive high end consumable before getting carried away with them and using your FV4005 as a light as the video suggests!
Use them wisely, don’t believe the hype!
TL;DR
Yes, they will improve your tank. No, they will not make you invincible and win more!