So much, bro. Like, it's not comparable at all, I have no idea where people get this idea that a scrim is the same level as any tournament game, no matter how "mickey mouse." The only explanation I can think of is huge huffs of copium.
Ok, sure, T1 teams are not literally sweating their titts off, crying themselves to sleep at night if they don't win a Nights Monthly. But it is a lot different to a scrim.
In a scrim you are full practice mode, trying new strats, sometimes deliberately ecoing or forcing to practice certain conditions. You might even ask the other team to go unlimited money in a round to try something new. You have ghost mode on to ensure all your setups are 100% every round, etc.
The conditions are just not at all the same as a tournament game, which has a full ruleset you could be disqualified for not following. For a minor tournament you are praccing tournament conditions and playing according to a gameplan, so naturally if you begin to lose it's frustrating... therefore, there is an element of competitiveness. No T1 team wants to just enter a tournament a lose, and then go "oh well, just a scrim, am I right? tehehe".
No, nobody is doing that. If they say that they're coping.
I have never scrimmed to T1 level, I am not claiming to be a pro. However, I have played some very decent T2/T3 teams in EMEA, and competed in minor tournaments. When I was younger I played CS to a high level. I think have a good feeling for the scene and how players react to different conditions.