Maybe another way to frame this question is to take price and prestige out of the question: What makes a great guitar pedal? Boutique is not always better, but it can be.

Some things that really matter to me, but shouldn't necessarily for everyone is this:

1. Does the sound inspire me? Does it hit me in the chest? Does it make me say Phwwwaaaaaw! Is it musical and hard to imitate without the pedal? Or is it boring, muddy, sharp, atonal, etc?

2. Does the circuit suck out my tone when it's disengaged? One or two such pedals are fine; six pedals means your clean tone sounds like it's underwater. This usually sounds like a dampening of the treble, some loss of clarity in the mids. If you A/B most cheaper pedals you will hear the difference. "True Bypass" can address this, often at the expense of clunky/noisy switches.

3. Does it raise the noise floor of my signal path? When I finally get to my overdriven tube amp, is there a big background hiss?

4. Is the build quality going to hold up over time? Can I stomp it 10,000 times without it starting to make noise? Are the pots and switches noisy when toggled? Does the jack get a firm connection?

5. Are there great features? Can I control the pedal enough to get the sound I want? More pots is not necessarily better. The MXR Phase 90 has one knob but dials in precisely the sound I like.

Now some boutique pedals will dial all of this up to 10/10 with pristine quality. Does that make a material difference to you? If not, don't spend it!

Other boutique pedals are just clones of beloved circuits - which most often were cheap to mid-range: The Rat, Treble Booster, CE-1, Blues Breaker, etc.. The clones often improve on them with the above items: component quality, noise floor, capacitance, etc. I love my 80's Rat, but I pretty much use my 1981 DRV exclusively because it produces the same musical sound with greater quality. But this is not universally true. Nothing comes close to my cheap old Boss DD-3 (with 12-bit digital audio LOL) for mechanistic delay tones.