The look pretty but have no benefit on standard engines over good condition standard items.
On engines producing high boost and vacuums they are less likely to burst or collapse.
They should last longer than standard ones on a standard engine and a lot longer on tuned ones. Whether the extra cost is worth it on a standard car is a matter for the owner.
PS. Don't confuse silicone with silicon, which is used in semiconductor electronics.
The intake pipe can collapse easily on some turbo's. The C20LET Vauxhall turbo engine was known for the intaqke pipe to collapse. The other thing with performance gains, they can create the same effect as braided hoses and wont expand as much as standard items can. Therefor will give a faster reaction time of the boost as it boosts up and pressurises. Other than that, cosmetic for the most part
My Cooper S has a muffler pipe coming in off the cold side of the turbo, down the intercooler. This has been proven to add UP TO 5bhp once removed and replaced with a none restrictive silicone pipe.