A large studio's patch notes can run to several thousand words across hundreds of individual changes. Nobody reads all of it. Nobody is supposed to. The document is structured for accountability rather than for usability, which means the information you need is present but not prioritised.
There is a reliable way to cut through it.
Start at the end, not the beginning
Most notes put general fixes, bug reports, and credits in the final third. The opening section is normally the headline content: new areas, new items, reworks. If you are checking whether your current build still works, skip straight to the balance and bugfix sections.
Studios that write good notes include a summary or highlights section. When one exists, it is genuinely worth reading, because it is the only part written for a player rather than for a changelog archive.
Look for reworks specifically
The changes most likely to affect you are labelled differently from the rest. Studios use a small set of terms consistently: a rework is a substantial redesign of an existing ability or item, a rebalance is a numerical adjustment, a nerf is a reduction, and a buff is an increase.
A rework matters more than any number of balance changes because it can invalidate how you used something. If you built a character or a loadout around an ability that gets reworked, you need to know regardless of whether the raw numbers went up or down.
Check the fixes for silent behaviour changes
Bugfix sections hide the most disruptive changes. A fix for an ability that now triggers twice where it previously triggered once is a huge change and appears in notes as a single line about an unintended trigger. The same applies to anything described as now working as intended, which means it was previously not working as intended and your build was working around a bug.
Read the bugfix section like it contains balance changes. Frequently it does.
The deprecation warning
Look for language about something being removed, renamed, or having its previous behaviour locked behind an option. Deprecation is how studios make a change without invalidating existing saves outright. The old behaviour usually still exists, but you may need to opt back into it, and the option sometimes disappears in a later patch.