Is a power supply beneficial for component SQ if you have a quality power conditioner?

Yes, jond is spot on.
Regarding interference produced by wall warts, some digital devices can backwash noise down their AC line. That's why their power supplies need to have good voltage regulation and a design to minimize this. It also helps to use a shielded power cord and isolate digital from the analogue power source.

I would say that the component using a wall-wart is not living up to its potential. Even if it creates noise into the power line that may or may not be audible, a well built LPS will help your streamer perform at a higher level.

However, a company like iFi makes switching power supplies (SMPS) which are receiving good reviews. Still, I don't know if they would equal a LPS.

easola, there are many components or devices that come standard with a wall-wart (a switch-mode PS) and offer an external LPS at additional cost. Some of these power supply upgrades can be very costly. That's why we've been discussing aftermarket power supplies as a cheaper alternative, many built in China.
As whart has explained, a bench PS can cost less and have more features than so-called "audio" or "audiophile" linear power supplies.

The better supplies use a toroidal or a Rcore transformer and very different filtering than SMPS.

Some flaws of the SMPS design (from Wikipedia)...
Noisier due to the switching frequency of the SMPS. An unfiltered output may cause glitches in digital circuits or noise in audio circuits.

Very low cost SMPS may couple electrical switching noise back onto the mains power line, causing interference with A/V equipment connected to the same phase. Non power-factor-corrected SMPSs also cause harmonic distortion.

https://en.wikipedia.org/wiki/Switched-mode_power_supply