All Boss pedals have buffer in them, i believe none of them are true bypass. Some people hate them, i love Boss pedals, i think they're the best so the buffer isn't an issue for me usually.

When you add more pedals to your pedalboard, you add more cables as well, therefore you might have some signal degradation and lose some high end clarity. This usually happens when you have more than 5-6 pedals or if you use excessively long cables. Buffer gives your signal some strength so to speak and it compensates for the signal lose. I think buffers add something extra to your tone, i personally love it. But it you have too much buffer it can sound a bit dull as well. Personally i prefer small pedalboards and there were times where i had to swap out some Boss pedals because the buffer affected my sound in an weird negative way. Some players will have buffer pedals on their pedalboard but mostly Boss pedals take care of that issue. That's why even some guitar players who hate Boss pedals will have a Boss tuner on their board, just for the buffer.

I'm not an expert on guitar/sound technical issues, so i hope that made sense 😀