I just want to add my answer here for further opinions, but I think David Sleet's answer is excellent anyway.
As a small aside, for tournaments I'd say it's a quick way to the door. It's too much of your often short stack when the same can be accomplished with a 2.5x raise.
Now for cash, that is a pretty different beast. You said your normal raise is 3.5x, which is fine, but often you have to adjust to what the table is doing. As others have mentioned there is no such thing a fixed number that you can sit down every time and open with it on 100% of tables. It doesn't work like that. The most profitable initial bet is simple, it's firstly what thins the field, but gets one or two callers(if you want them to call) and it's an amount you're comfortable putting in(this is key, if you're not comfortable you're not thinking about the best play but rather the money involved).
I've played on tables where a 7-8x was the open raise, and anything lower than that was a family pot, which is in the long run not profitable for anyone. To contrast this I've played on tables where you so much as go above the 2.5x raise and the pot is yours.
As David Sleet mentioned in his answer you need to adjust. If you never adjust and follow the same pattern, then I'm sorry to say it you're missing value nearly every game you play. Assume you have a good hand and want callers, a bet of too much that won't be called is missed value, a bet that is called when they would have called more is also missed value. Now it's not an easy thing to pick up on all the time, but you still need to try if you want to maximise your profitability.
Two examples, you have Aces both tables:
- You're against a tight player who just won't call big raises, if it's above 3x they normally fold unless upper end of range, you raise 4x, they fold. Great you won the pot, but you missed out on the extra 3BBs you could have gotten.
- You're against a very loose player, they like to see flops, they're having a good time and have been calling a lot. You open to 4x, they call, hand continues. But this type of player would probably have called 5x,6x,7x, or maybe even a 10x raise. By not adjusting your open you've missed BBs from this player.
Poker is not a static game, every game you play in is unique in it's own way, all with their own unique cast of players. You need to understand what works on each table, with each player and adapt your play to maximise your profitability.