Toners were invented when soap left skin alkaline and needed to be rebalanced. Modern cleansers don't disrupt skin pH. The toner step has mostly become marketing.
What 'modern toners' actually are
Hydrating toners are really thin essences (same job as a hydrating serum). Exfoliating toners are really leave-on acid serums. Astringent toners are leftover from the 80s and damage the barrier. None replace dedicated products.
When to keep a toner step
If you specifically enjoy the ritual. If you're using the seven-skin Korean layering method (specific approach). If your only acid is in toner form (then it's your active step, not your toner step). Otherwise, dropping it changes nothing.
Skip toner for a month. Most users notice no negative change. Routines tighten, money saved, results unchanged.