The article claims at the start "There are more than 45,000 denominations globally." Its source is
this page which explains how broadly it uses the term "denomination":
The most detailed level of our taxonomy of global Christianity is Christian denominations, defined as an organized Christian church, tradition, religious group, community of people, aggregate of worship centre, usually within a specific country, whose component congregations and members are called by the same name in different areas, regarding themselves as an autonomous Christian church distinct from other churches and traditions. Denominations are defined and measured at the country level, creating a large number of separate denominations within Christian families and Christian traditions. For example, the presence of the Catholic Church in the world’s 234 countries results in 234 Catholic “denominations”, though these can be further subdivided by rite (e.g., Byzantine or Latin). The typical way for Christians to count themselves is at the local congregational level and then aggregate these totals at the city, province, state, regional and finally, national levels.
Individual congregations are not counted as “denominations.” We do make note of the fact that many independent congregations are not a part of any denomination. If those churches were to form an independent network with a name, we would consider them a denomination. Using this method, we report 45,000 Christian denominations in the world in 2019.
It seems to me that any methodology that counts the Catholic Church as 234 denominations is perhaps using the term "denomination" very, very loosely.
I suppose this doesn't fully negate the point that "Christians disagree with each other and there's a bunch of denominations" but let's not exaggerate it into numbers like 46,000.