"There's a reason they build appellate courts," is what my old boss used to say about cases we would consider appealing. In civil and criminal cases, generally there is the right to one appeal of the trial court's final decision(s).
So, if the outcome of most any trial can be appealed at least once, should you appeal? That depends on options (usually by this stage minimal), budget, time involved, goals of the case etc., and of course the chances of a favorable outcome. The rate of reversal or similar is about 25% in state cases, and just over 10% in federal cases. Far fewer cases end up at the highest appellate courts, like the applicable state or U.S. supreme court, mostly because those appeals are discretionary, meaning the appellate judges themselves decide whether to accept the appeal. The likelihood of this is less than 10% (although once accepted, the reversal etc. rate approaches 50%).
Appeals take time - framing the issues, preparing and filing the notice, compiling and reviewing the appeal record, researching law, drafting and crafting written briefs, preparing and handling any oral argument (also usually discretionary), and the like. Two years to complete an appeal is not out of the ordinary. Because time is money, appeals can cost many thousands.
Many appellate decisions - the written opinion disposing of the matter usually authored by one appellate judge on behalf of a panel of three or more - are published and become precedent for future cases. Transactional lawyers, regulatory lawyers and other non-litigators typically do not try or appeal cases, but they are guided by those precedents.
Trial judges make mistakes too, and that is why they build appellate courts.
-courtesy of Sanderson Law, P.C., handling appeals, trials and everything in between, since 1992. 303-444-8846.