As one of Magic the Gathering's youngest formats, Pioneer is changing and growing at an accelerated pace. Evolving alongside the meta of the format is the banlist, which was created to regulate the format. Some things were banned early on to help shape Pioneer's identity uniquely to differentiate between itself and Modern. Other things were banned as it was found they hurt the competitive diversity of the format or were simply too strong. Each card has its own reason, so being able to quickly reference Pioneer's dynamic banlist is helpful for MtG players.
Source：https://www.cbr.com/mtg-pioneer-banlist-guide/
